Adds isPublicAddress function to Wallet

.gitignore

@@ -1,3 +1,4 @@
 vendor/
 composer.lock
-.DS_Store
+.DS_Store
+/.idea

src/Wallet.php

@@ -93,6 +93,28 @@ public function isPublicKey($key)
         return true;
     }
 
+    public function isPublicAddress($address)
+    {
+        $length = 42;
+        if (strlen($address) !== $length) {
+            return false;
+        }
+
+        $parts = explode('x', $address);
+        $last_part = array_pop($parts);
+        $first_part = $parts[0] . 'x';
+
+        if ($first_part !== 'hx' && strlen($first_part) !== $length - 40) {
+            return false;
+        }
+
+        if (!ctype_xdigit($last_part) && strlen($last_part) !== $length - 2) {
+            return false;
+        }
+
+        return true;
+    }
+
     /**
      * @return string
      */
@@ -118,6 +140,4 @@ public function getPublicAddress(): string
     }
 
 
-
-
 }

tests/WalletTest.php

@@ -1,5 +1,6 @@
 <?php
 
+use mitsosf\IconSDK\Wallet;
 use PHPUnit\Framework\TestCase;
 
 
@@ -65,4 +66,12 @@ public function test_pubkeyToAddress(){
 
         unset($var);
     }
+
+    public function test_isPublicAddress(){
+        $var = new mitsosf\IconSDK\Wallet;
+
+        $this->assertTrue($var->isPublicAddress($this->public_address));
+        $this->assertFalse($var->isPublicAddress('h'.$this->public_address));
+        unset($var);
+    }
 }