Creates a textual file with the content provided as docstring.

def step_a_file_named_filename_with(context, filename):
    """Creates a textual file with the content provided as docstring."""
    step_a_file_named_filename_and_encoding_with(context, filename, "UTF-8")

    # -- SPECIAL CASE: For usage with behave steps.
    if filename.endswith(".feature"):
        command_util.ensure_context_attribute_exists(context, "features", [])
        context.features.append(filename)