<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def write_table_to_file(self, dtype, custom_name=None, append=False, dir_path=None):
 """ Write out a MagIC table to file, using custom filename as specified in self.filenames. Parameters dtype : str magic table name """

        if custom_name:
            fname = custom_name
        else:
            fname = self.filenames[dtype]
        if not dir_path:
            dir_path=self.directory
        if dtype in self.tables:
            write_df = self.remove_names(dtype)
            outfile = self.tables[dtype].write_magic_file(custom_name=fname,
                                                          dir_path=dir_path,
                                                          append=append, df=write_df)
        return outfile