def METHOD_NAME(name):
    """
    Get a force field from the distributed library knowing its name.
    Parameters
    ----------
    name: str
        The name of the requested force field.
    Returns
    -------
    ForceField
    Raises
    ------
    KeyError
        There is no force field with the requested name in the distributed
        library.
    """
    # This function is a *temporary* solution. It reads all the distributed
    # force fields and keep a cache of them. A better solution would only parse
    # the requested force field! There would still be a need to cache the read
    # force fields, though. Indeed, force field comparison is based on instance
    # identity,so we want each force field to be  singleton.
    # TODO: Implement a better way to request a force field by name.
    global _FORCE_FIELDS
    try:
        return _FORCE_FIELDS[name]
    except KeyError:
        _FORCE_FIELDS = find_force_fields(os.path.join(DATA_PATH, 'force_fields'))
        return _FORCE_FIELDS[name]