def METHOD_NAME(self, context, data_dict, fields_types):
    '''Validates the ``data_dict`` sent by the user
    This is the first method that's called. It's used to guarantee that
    there aren't any unrecognized parameters, so other methods don't need
    to worry about that.
    You'll need to go through the received ``data_dict`` and remove
    everything that you understand as valid. For example, if your extension
    supports an ``age_between`` filter, you have to remove this filter from
    the filters on the ``data_dict``.
    The same ``data_dict`` will be passed to every IDatastore extension in
    the order they've been loaded (the ``datastore`` plugin will always
    come first). One extension will get the resulting ``data_dict`` from
    the previous extensions. In the end, if the ``data_dict`` is empty, it
    means that it's valid. If not, it's invalid and we throw an error.
    Attributes on the ``data_dict`` that can be comma-separated strings
    (e.g. fields) will already be converted to lists.
    :param context: the context
    :type context: dictionary
    :param data_dict: the parameters received from the user
    :type data_dict: dictionary
    :param fields_types: the current resource's fields as dict keys and
        their types as values
    :type fields_types: dictionary
    '''
    return data_dict