diff --git a/.idea/bitly-shorten.iml b/.idea/bitly-shorten.iml
new file mode 100644
index 0000000..d6ebd48
--- /dev/null
+++ b/.idea/bitly-shorten.iml
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$" />
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>
\ No newline at end of file
diff --git a/.idea/modules.xml b/.idea/modules.xml
new file mode 100644
index 0000000..edbcc81
--- /dev/null
+++ b/.idea/modules.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/bitly-shorten.iml" filepath="$PROJECT_DIR$/.idea/bitly-shorten.iml" />
+    </modules>
+  </component>
+</project>
\ No newline at end of file
diff --git a/src/main/kotlin/net/thauvin/erik/bitly/Bitlinks.kt b/src/main/kotlin/net/thauvin/erik/bitly/Bitlinks.kt
index 58bd057..e74877a 100644
--- a/src/main/kotlin/net/thauvin/erik/bitly/Bitlinks.kt
+++ b/src/main/kotlin/net/thauvin/erik/bitly/Bitlinks.kt
@@ -69,25 +69,25 @@ open class Bitlinks(private val accessToken: String) {
     @Synchronized
     @JvmOverloads
     fun clicks(
-            bitlink: String,
-            unit: Units = Units.DAY,
-            units: Int = -1,
-            size: Int = 50,
-            unit_reference: String = Constants.EMPTY,
-            toJson: Boolean = false
+        bitlink: String,
+        unit: Units = Units.DAY,
+        units: Int = -1,
+        size: Int = 50,
+        unit_reference: String = Constants.EMPTY,
+        toJson: Boolean = false
     ): String {
         var clicks = if (toJson) Constants.EMPTY_JSON else Constants.EMPTY
         if (bitlink.isNotBlank()) {
             lastCallResponse = Utils.call(
-                    accessToken,
-                    ("/bitlinks/${bitlink.removeHttp()}/clicks/summary").toEndPoint(),
-                    mapOf(
-                            "unit" to unit.toString().lowercase(),
-                            "units" to units.toString(),
-                            "size" to size.toString(),
-                            "unit_reference" to unit_reference
-                    ),
-                    Methods.GET
+                accessToken,
+                ("/bitlinks/${bitlink.removeHttp()}/clicks/summary").toEndPoint(),
+                mapOf(
+                    "unit" to unit.toString().lowercase(),
+                    "units" to units.toString(),
+                    "size" to size.toString(),
+                    "unit_reference" to unit_reference
+                ),
+                Methods.GET
             )
             clicks = parseJsonResponse(lastCallResponse, "total_clicks", clicks, toJson)
         }
@@ -108,26 +108,26 @@ open class Bitlinks(private val accessToken: String) {
     @Synchronized
     @JvmOverloads
     fun create(
-            domain: String = Constants.EMPTY,
-            title: String = Constants.EMPTY,
-            group_guid: String = Constants.EMPTY,
-            tags: Array<String> = emptyArray(),
-            deeplinks: Array<Map<String, String>> = emptyArray(),
-            long_url: String,
-            toJson: Boolean = false
+        domain: String = Constants.EMPTY,
+        title: String = Constants.EMPTY,
+        group_guid: String = Constants.EMPTY,
+        tags: Array<String> = emptyArray(),
+        deeplinks: Array<Map<String, String>> = emptyArray(),
+        long_url: String,
+        toJson: Boolean = false
     ): String {
         var link = if (toJson) Constants.EMPTY_JSON else Constants.EMPTY
         if (long_url.isNotBlank()) {
             lastCallResponse = Utils.call(
-                    accessToken,
-                    "/bitlinks".toEndPoint(),
-                    mutableMapOf<String, Any>("long_url" to long_url).apply {
-                        if (domain.isNotBlank()) put("domain", domain)
-                        if (title.isNotBlank()) put("title", title)
-                        if (group_guid.isNotBlank()) put("group_guid", group_guid)
-                        if (tags.isNotEmpty()) put("tags", tags)
-                        if (deeplinks.isNotEmpty()) put("deeplinks", deeplinks)
-                    }
+                accessToken,
+                "/bitlinks".toEndPoint(),
+                mutableMapOf<String, Any>("long_url" to long_url).apply {
+                    if (domain.isNotBlank()) put("domain", domain)
+                    if (title.isNotBlank()) put("title", title)
+                    if (group_guid.isNotBlank()) put("group_guid", group_guid)
+                    if (tags.isNotEmpty()) put("tags", tags)
+                    if (deeplinks.isNotEmpty()) put("deeplinks", deeplinks)
+                }
             )
             link = parseJsonResponse(lastCallResponse, "link", link, toJson)
         }
@@ -149,9 +149,9 @@ open class Bitlinks(private val accessToken: String) {
         var longUrl = if (toJson) Constants.EMPTY_JSON else Constants.EMPTY
         if (bitlink_id.isNotBlank()) {
             lastCallResponse = Utils.call(
-                    accessToken,
-                    "/expand".toEndPoint(),
-                    mapOf("bitlink_id" to bitlink_id.removeHttp())
+                accessToken,
+                "/expand".toEndPoint(),
+                mapOf("bitlink_id" to bitlink_id.removeHttp())
             )
             longUrl = parseJsonResponse(lastCallResponse, "long_url", longUrl, toJson)
         }
@@ -198,10 +198,10 @@ open class Bitlinks(private val accessToken: String) {
     @Synchronized
     @JvmOverloads
     fun shorten(
-            long_url: String,
-            group_guid: String = Constants.EMPTY,
-            domain: String = Constants.EMPTY,
-            toJson: Boolean = false
+        long_url: String,
+        group_guid: String = Constants.EMPTY,
+        domain: String = Constants.EMPTY,
+        toJson: Boolean = false
     ): String {
         var bitlink = if (toJson) Constants.EMPTY_JSON else long_url
         if (!long_url.isValidUrl()) {
@@ -234,39 +234,39 @@ open class Bitlinks(private val accessToken: String) {
     @Synchronized
     @JvmOverloads
     fun update(
-            bitlink: String,
-            references: Map<String, String> = emptyMap(),
-            archived: Boolean = false,
-            tags: Array<String> = emptyArray(),
-            created_at: String = Constants.EMPTY,
-            title: String = Constants.EMPTY,
-            deeplinks: Array<Map<String, String>> = emptyArray(),
-            created_by: String = Constants.EMPTY,
-            long_url: String = Constants.EMPTY,
-            client_id: String = Constants.EMPTY,
-            custom_bitlinks: Array<String> = emptyArray(),
-            link: String = Constants.EMPTY,
-            id: String = Constants.EMPTY,
-            toJson: Boolean = false
+        bitlink: String,
+        references: Map<String, String> = emptyMap(),
+        archived: Boolean = false,
+        tags: Array<String> = emptyArray(),
+        created_at: String = Constants.EMPTY,
+        title: String = Constants.EMPTY,
+        deeplinks: Array<Map<String, String>> = emptyArray(),
+        created_by: String = Constants.EMPTY,
+        long_url: String = Constants.EMPTY,
+        client_id: String = Constants.EMPTY,
+        custom_bitlinks: Array<String> = emptyArray(),
+        link: String = Constants.EMPTY,
+        id: String = Constants.EMPTY,
+        toJson: Boolean = false
     ): String {
         var result = if (toJson) Constants.EMPTY_JSON else Constants.FALSE
         if (bitlink.isNotBlank()) {
             lastCallResponse = Utils.call(
-                    accessToken, "/bitlinks/${bitlink.removeHttp()}".toEndPoint(), mutableMapOf<String, Any>().apply {
-                if (references.isNotEmpty()) put("references", references)
-                if (archived) put("archived", archived)
-                if (tags.isNotEmpty()) put("tags", tags)
-                if (created_at.isNotBlank()) put("created_at", created_at)
-                if (title.isNotBlank()) put("title", title)
-                if (deeplinks.isNotEmpty()) put("deeplinks", deeplinks)
-                if (created_by.isNotBlank()) put("created_by", created_by)
-                if (long_url.isNotBlank()) put("long_url", long_url)
-                if (client_id.isNotBlank()) put("client_id", client_id)
-                if (custom_bitlinks.isNotEmpty()) put("custom_bitlinks", custom_bitlinks)
-                if (link.isNotBlank()) put("link", link)
-                if (id.isNotBlank()) put("id", id)
-            },
-                    Methods.PATCH
+                accessToken, "/bitlinks/${bitlink.removeHttp()}".toEndPoint(), mutableMapOf<String, Any>().apply {
+                    if (references.isNotEmpty()) put("references", references)
+                    if (archived) put("archived", archived)
+                    if (tags.isNotEmpty()) put("tags", tags)
+                    if (created_at.isNotBlank()) put("created_at", created_at)
+                    if (title.isNotBlank()) put("title", title)
+                    if (deeplinks.isNotEmpty()) put("deeplinks", deeplinks)
+                    if (created_by.isNotBlank()) put("created_by", created_by)
+                    if (long_url.isNotBlank()) put("long_url", long_url)
+                    if (client_id.isNotBlank()) put("client_id", client_id)
+                    if (custom_bitlinks.isNotEmpty()) put("custom_bitlinks", custom_bitlinks)
+                    if (link.isNotBlank()) put("link", link)
+                    if (id.isNotBlank()) put("id", id)
+                },
+                Methods.PATCH
             )
 
             if (lastCallResponse.isSuccessful) {
diff --git a/src/main/kotlin/net/thauvin/erik/bitly/Bitly.kt b/src/main/kotlin/net/thauvin/erik/bitly/Bitly.kt
index c602867..8c665e4 100644
--- a/src/main/kotlin/net/thauvin/erik/bitly/Bitly.kt
+++ b/src/main/kotlin/net/thauvin/erik/bitly/Bitly.kt
@@ -49,7 +49,7 @@ open class Bitly() {
      * [Authentication](https://dev.bitly.com/docs/getting-started/authentication).
      **/
     var accessToken: String = System.getenv(Constants.ENV_ACCESS_TOKEN)
-            ?: (System.getProperty(Constants.ENV_ACCESS_TOKEN) ?: Constants.EMPTY)
+        ?: (System.getProperty(Constants.ENV_ACCESS_TOKEN) ?: Constants.EMPTY)
 
     /**
      * Creates a new instance using an [API Access Token][accessToken].
diff --git a/src/main/kotlin/net/thauvin/erik/bitly/Utils.kt b/src/main/kotlin/net/thauvin/erik/bitly/Utils.kt
index 98e14c3..8c74770 100644
--- a/src/main/kotlin/net/thauvin/erik/bitly/Utils.kt
+++ b/src/main/kotlin/net/thauvin/erik/bitly/Utils.kt
@@ -50,7 +50,7 @@ import java.util.logging.Logger
 open class Utils private constructor() {
     companion object {
         /** The logger instance. */
-        val logger: Logger by lazy { Logger.getLogger(Bitly::class.java.name) }
+        val logger: Logger by lazy { Logger.getLogger(Utils::class.java.name) }
 
         /**
          * Executes an API call.
@@ -70,8 +70,7 @@ open class Utils private constructor() {
         ): CallResponse {
             val response = CallResponse()
             if (validateCall(accessToken, endPoint)) {
-                val apiUrl = endPoint.toHttpUrlOrNull()
-                if (apiUrl != null) {
+                endPoint.toHttpUrlOrNull()?.let { apiUrl ->
                     val builder = when (method) {
                         Methods.POST, Methods.PATCH -> {
                             val formBody = JSONObject(params).toString()
@@ -117,8 +116,7 @@ open class Utils private constructor() {
         }
 
         private fun parseBody(endPoint: String, result: Response): String {
-            val body = result.body?.string()
-            if (body != null) {
+            result.body?.string()?.let { body ->
                 if (!result.isSuccessful && body.isNotEmpty()) {
                     try {
                         with(JSONObject(body)) {
diff --git a/src/test/kotlin/net/thauvin/erik/bitly/BitlyTest.kt b/src/test/kotlin/net/thauvin/erik/bitly/BitlyTest.kt
index d2657b0..454418f 100644
--- a/src/test/kotlin/net/thauvin/erik/bitly/BitlyTest.kt
+++ b/src/test/kotlin/net/thauvin/erik/bitly/BitlyTest.kt
@@ -32,16 +32,14 @@
 
 package net.thauvin.erik.bitly
 
+import net.thauvin.erik.bitly.Utils.Companion.isValidUrl
 import net.thauvin.erik.bitly.Utils.Companion.removeHttp
 import net.thauvin.erik.bitly.Utils.Companion.toEndPoint
 import org.json.JSONObject
 import org.junit.Before
 import java.io.File
 import java.util.logging.Level
-import kotlin.test.Test
-import kotlin.test.assertEquals
-import kotlin.test.assertNotEquals
-import kotlin.test.assertTrue
+import kotlin.test.*
 
 class BitlyTest {
     private val bitly = with(File("local.properties")) {
@@ -74,8 +72,8 @@ class BitlyTest {
     fun `token should be valid`() {
         val test = Bitly().apply { accessToken = "12345679" }
         assertEquals(
-                "{\"message\":\"FORBIDDEN\"}",
-                test.bitlinks().shorten("https://erik.thauvin.net/blog", toJson = true)
+            "{\"message\":\"FORBIDDEN\"}",
+            test.bitlinks().shorten("https://erik.thauvin.net/blog", toJson = true)
         )
     }
 
@@ -89,6 +87,11 @@ class BitlyTest {
         assertEquals(shortUrl, bitly.bitlinks().shorten(shortUrl))
     }
 
+    @Test
+    fun `endPoint should be specified`() {
+        assertFalse(bitly.call("").isSuccessful)
+    }
+
     @Test
     fun `shorten = expand`() {
         val shortUrl = bitly.bitlinks().shorten(longUrl, domain = "bit.ly")
@@ -102,19 +105,23 @@ class BitlyTest {
 
     @Test
     fun `get user`() {
-        assertTrue(bitly.call("/user".toEndPoint(), method = Methods.GET).isSuccessful)
+        assertTrue(bitly.call("user".toEndPoint(), method = Methods.GET).isSuccessful)
+        assertTrue(
+            Utils.call(bitly.accessToken, "/user".toEndPoint(), method = Methods.GET).isSuccessful,
+            "call(/user)"
+        )
     }
 
     @Test
     fun `created by`() {
         assertEquals(
-                "ethauvin",
-                JSONObject(
-                        bitly.call(
-                                "/bitlinks/${shortUrl.removeHttp()}".toEndPoint(),
-                                method = Methods.GET
-                        ).body
-                ).getString("created_by")
+            "ethauvin",
+            JSONObject(
+                bitly.call(
+                    "/bitlinks/${shortUrl.removeHttp()}".toEndPoint(),
+                    method = Methods.GET
+                ).body
+            ).getString("created_by")
         )
     }
 
@@ -154,14 +161,18 @@ class BitlyTest {
 
     @Test
     fun `create bitlink`() {
+        assertTrue(
+            bitly.bitlinks().create(long_url = longUrl).matches("https://\\w+.\\w{2}/\\w{7}".toRegex()),
+            "just long_url"
+        )
         assertEquals(
-                shortUrl,
-                bitly.bitlinks().create(
-                        domain = "bit.ly",
-                        title = "Erik's Blog",
-                        tags = arrayOf("erik", "thauvin", "blog", "weblog"),
-                        long_url = longUrl
-                )
+            shortUrl,
+            bitly.bitlinks().create(
+                domain = "bit.ly",
+                title = "Erik's Blog",
+                tags = arrayOf("erik", "thauvin", "blog", "weblog"),
+                long_url = longUrl
+            )
         )
     }
 
@@ -169,11 +180,21 @@ class BitlyTest {
     fun `update bitlink`() {
         val bl = bitly.bitlinks()
         assertEquals(
-                Constants.TRUE,
-                bl.update(shortUrl, title = "Erik's Weblog", tags = arrayOf("blog", "weblog"))
+            Constants.TRUE,
+            bl.update(shortUrl, title = "Erik's Weblog", tags = arrayOf("blog", "weblog"))
+        )
+
+        assertTrue(
+            bl.update(shortUrl, tags = emptyArray(), toJson = true).contains("\"tags\":[]"), "update tags toJson"
         )
 
         bl.update(shortUrl, link = longUrl)
         assertTrue(bl.lastCallResponse.isUnprocessableEntity, "422 Unprocessable")
     }
+
+    @Test
+    fun `validate URL`() {
+        assertTrue("https://www.example.com".isValidUrl(), "valid url")
+        assertFalse("this is a test".isValidUrl(), "invalid url")
+    }
 }