fix(Transfers): Fix setHolder warning when called before setTransfers (…

…#184).

src/Resource/Transfers.php

@@ -50,6 +50,16 @@ protected function populate(stdClass $response)
         return $transfers;
     }
 
+    /**
+     * Initializes new transferInstrument instance if it doesn't exist
+     */
+    private function intializeTransferInstrument()
+    {
+        if (!isset($this->data->transferInstrument)) {
+            $this->data->transferInstrument = new stdClass();
+        }
+    }
+
     /**
      * Set info of transfers.
      *
@@ -71,7 +81,7 @@ public function setTransfers(
         $accountCheckNumber
     ) {
         $this->data->amount = $amount;
-        $this->data->transferInstrument = new stdClass();
+        $this->intializeTransferInstrument();
         $this->data->transferInstrument->method = self::METHOD;
         $this->data->transferInstrument->bankAccount = new stdClass();
         $this->data->transferInstrument->bankAccount->type = self::TYPE;
@@ -92,6 +102,7 @@ public function setTransfers(
      */
     public function setHolder($fullname, $taxDocument)
     {
+        $this->intializeTransferInstrument();
         $this->data->transferInstrument->bankAccount->holder = new stdClass();
         $this->data->transferInstrument->bankAccount->holder->fullname = $fullname;
         $this->data->transferInstrument->bankAccount->holder->taxDocument = new stdClass();