def custom_function(func, input_files, output_file):
from .modules import utils<EOL>return {<EOL>'<STR_LIT>': utils.no_dependencies,<EOL>'<STR_LIT>': func,<EOL>'<STR_LIT:input>': input_files,<EOL>'<STR_LIT>': output_file,<EOL>'<STR_LIT>': {},<EOL>}<EOL>
Calls a custom function which must create the output file.

The custom function takes 3 parameters: ``input_files``,
``output_file`` and a boolean ``release``.