original_string: function get_first_date_last_month($m=1) {
      return $this->mdate($this->dateFormat, mktime(0, 0, 0, $this->mdate("m")-$m, 1, $this->mdate("Y")));
    }
code: function get_first_date_last_month($m=1) {
      return $this->mdate($this->dateFormat, mktime(0, 0, 0, $this->mdate("m")-$m, 1, $this->mdate("Y")));
    }
code_tokens: function get_first_date_last_month ( $ m = 1 ) { return $ this -> mdate ( $ this -> dateFormat , mktime ( 0 , 0 , 0 , $ this -> mdate ( "m" ) - $ m , 1 , $ this -> mdate ( "Y" ) ) ) ; }
docstring: Return first date of last month
docstring_tokens: Return first date of last month