reflection.php
public function isAbstractMethodInParents($name)
    {
        $interface = new ReflectionClass($this->interface);
        $parent    = $interface->getParentClass();
        while ($parent) {
            if (! $parent->hasMethod($name)) {
                return false;
            }
            if ($parent->getMethod($name)->isAbstract()) {
                return true;
            }
            $parent = $parent->getParentClass();
        }

        return false;
    }
public function isAbstractMethodInParents($name)
    {
        $interface = new ReflectionClass($this->interface);
        $parent    = $interface->getParentClass();
        while ($parent) {
            if (! $parent->hasMethod($name)) {
                return false;
            }
            if ($parent->getMethod($name)->isAbstract()) {
                return true;
            }
            $parent = $parent->getParentClass();
        }

        return false;
    }
Checks whether a method is abstract in all parents or not.

@param string $name Method name.

@return bool true if method is abstract in parent, else false