Fix issue that popup methods are rendered twice (See #4).

src/Netzmacht/LeafletPHP/Encoder/UIEncoder.php

@@ -77,8 +77,6 @@ public function encodePopup(Popup $popup, Encoder $encoder)
             $source ? (', ' . $encoder->encodeReference($source)) : ''
         );
 
-        $buffer .= $this->encodeMethodCalls($popup->getMethodCalls(), $encoder);
-
         return $buffer;
     }
 }

tests/Encoder/UIEncoderTest.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace Netzmacht\LeafletPHP\Test\Encoder;
+
+use Netzmacht\JavascriptBuilder\Type\AnonymousFunction;
+use Netzmacht\LeafletPHP\Definition\UI\Popup;
+use Netzmacht\LeafletPHP\Test\TestCase;
+
+class UIEncoderTest extends TestCase
+{
+    public function testPopupMethodsAreRendered()
+    {
+        $leaflet = $this->getBuilder();
+
+        $popup = new Popup('popup');
+        $popup->on('add', (new AnonymousFunction())->addLine('console.log("add");'));
+
+        $this->assertSame(
+            'layers.popup = L.popup([]);'
+            . "\n"
+            . 'layers.popup.on("add", function() { console.log("add"); });',
+            $leaflet->encode($popup)
+        );
+    }
+}