def add_requirement_libs_from(self, req_libs, platforms=None):
    """Multi-platform dependency resolution for PEX files.

    :param builder: Dump the requirements into this builder.
    :param interpreter: The :class:`PythonInterpreter` to resolve requirements for.
    :param req_libs: A list of :class:`PythonRequirementLibrary` targets to resolve.
    :param log: Use this logger.
    :param platforms: A list of :class:`Platform`s to resolve requirements for.
                      Defaults to the platforms specified by PythonSetup.
    """
    reqs = [req for req_lib in req_libs for req in req_lib.requirements]
    self.add_resolved_requirements(reqs, platforms=platforms)