src/Execution/ResolveInfo.php
public function getFieldAST($fieldName)
    {
        $field = null;
        foreach ($this->getFieldASTList() as $fieldAST) {
            if ($fieldAST->getName() === $fieldName) {
                $field = $fieldAST;
                break;
            }
        }

        return $field;
    }
public function getFieldAST($fieldName)
    {
        $field = null;
        foreach ($this->getFieldASTList() as $fieldAST) {
            if ($fieldAST->getName() === $fieldName) {
                $field = $fieldAST;
                break;
            }
        }

        return $field;
    }
@param string $fieldName

@return null|Query|Field