def get_tag_value(self, spec, tag, byAbout, inPref=False, getMime=False):
        objTagParts = self.path_parts(byAbout, spec, tag, inPref)
        status, (value, value_type) = self._get_tag_value(objTagParts)
        if getMime:
            return status, (value if status == STATUS.OK else None, value_type)
        else:
            return status, (value if status == STATUS.OK else None)
Gets the value of a tag on an object identified by the
dataset/ETHPy150Open njr0/fish/fish/fishlib.py/Fluidinfo.get_tag_value