@classmethod
def from_spec_list(cls, specs, validator_map, resource_roots, package='sahara'
    ):
    """Constructs a list of validators from a list of specifications.

        :param specs: A list of validator specifications, each of which
            will be a dict of size 1, where the key represents the validator
            type and the value respresents its specification.
        :param validator_map: A map of validator name to class.
        :param resource_roots: The roots from which relative paths to
            resources (scripts and such) will be referenced. Any resource will
            be pulled from the first path in the list at which a file exists.
        :return: A list of validators.
        """
    validators = []
    for spec in specs:
        validator_class, validator_spec = cls.get_class_from_spec(spec,
            validator_map)
        validators.append(validator_class.from_spec(validator_spec,
            validator_map, resource_roots, package))
    return validators
