src/Invoice/Creator.php
protected function callSourceTypeSpecificMethod($method, $args = array())
    {
        $method .= $this->invoiceSource->getType();
        return call_user_func_array(array($this, $method), $args);
    }
protected function callSourceTypeSpecificMethod($method, $args = array())
    {
        $method .= $this->invoiceSource->getType();
        return call_user_func_array(array($this, $method), $args);
    }
protected function callSourceTypeSpecificMethod ( $ method , $ args = array ( ) ) { $ method .= $ this -> invoiceSource -> getType ( ) ; return call_user_func_array ( array ( $ this , $ method ) , $ args ) ; }
Calls a method constructed of the method name and the source type.

If the implementation/override of a method depends on the type of invoice
source it might be better to implement 1 method per source type. This
method calls such a method assuming it is named {method}{source-type}.
Example: if getLineItem($line) would be very different for an order
versus a credit note: do not override the base method but implement 2 new
methods getLineItemOrder($line) and getLineItemCreditNote($line).

@param string $method
@param array $args

@return mixed
Calls a method constructed of the method name and the source type .