'Return the the full path of the logo in the filesystem for the
given MAC address or None if no match is found
:param self: A MACMatcher object
:param mac_address: MAC address of the device
:type self: MACMatcher
:type mac_address: string
:return: The full path of the logo if MAC address if found and
None otherwise
:rtype: string or None'

def get_vendor_logo_path(self, mac_address):

    if (mac_address is None):
        return None
    mac_identifier = mac_address.replace(':', '').upper()[0:6]
    if (mac_identifier in self._mac_to_vendor):
        logo = self._mac_to_vendor[mac_identifier][1]
        logo_path = (constants.LOGOS_DIR + logo)
        if logo:
            return logo_path
        else:
            return None
