def singularity2docker(self, runscript="/bin/bash", force=False):
    '''convert a Singularity recipe to a (best estimated) Dockerfile'''

    recipe = [ "FROM %s" %self.fromHeader ]

    # Comments go up front!
    recipe += self.comments  

    # First add files, labels
    recipe += write_lines('ADD', self.files)
    recipe += write_lines('LABEL', self.labels)
    recipe += write_lines('ENV', self.environ)

    # Install routine is added as RUN commands
    recipe += write_lines('RUN', self.install)

    # Take preference for user, entrypoint, command, then default
    runscript = self._create_runscript(runscript, force)
    recipe.append('CMD %s' %runscript)

    if self.test is not None:
        recipe.append(write_lines('HEALTHCHECK', self.test))

    # Clean up extra white spaces
    return '\n'.join(recipe).replace('\n\n','\n')
convert a Singularity recipe to a (best estimated) Dockerfile