src/Carbon/CarbonPeriod.php
public function addFilter($callback, $name = null)
    {
        $tuple = $this->createFilterTuple(func_get_args());

        $this->filters[] = $tuple;

        $this->handleChangedParameters();

        return $this;
    }
public function addFilter($callback, $name = null)
    {
        $tuple = $this->createFilterTuple(func_get_args());

        $this->filters[] = $tuple;

        $this->handleChangedParameters();

        return $this;
    }
public function addFilter ( $ callback , $ name = null ) { $ tuple = $ this -> createFilterTuple ( func_get_args ( ) ) ; $ this -> filters [ ] = $ tuple ; $ this -> handleChangedParameters ( ) ; return $ this ; }
Add a filter to the stack.

@param callable $callback
@param string   $name

@return $this
Add a filter to the stack .