How to use the rosdep.osx.Osx function in rosdep

def __init__(self, packages, command = "rosdep", robust = False):
        os_list = [debian.RosdepTestOS(), debian.Debian(), debian.Ubuntu(), debian.Mint(), opensuse.OpenSuse(), redhat.Fedora(), redhat.Rhel(), arch.Arch(), osx.Osx(), gentoo.Gentoo(), cygwin.Cygwin(), freebsd.FreeBSD()]
        # Make sure that these classes are all well formed.  
        for o in os_list:
            if not isinstance(o, rosdep.base_rosdep.RosdepBaseOS):
                raise RosdepException("Class [%s] not derived from RosdepBaseOS"%o.__class__.__name__)
        # Detect the OS on which this program is running. 
        self.osi = roslib.os_detect.OSDetect(os_list)
        self.yc = YamlCache(self.osi.get_name(), self.osi.get_version(), self.osi.get_os().installers)
        self.packages = packages
        rp = roslib.packages.ROSPackages()
        self.rosdeps = rp.rosdeps(packages)
        self.robust = robust