def _realize(self, container, names, value):
        """
        Complete the initialization of this L{FlagConstant}.

        This implementation differs from other C{_realize} implementations in
        that a L{FlagConstant} may have several names which apply to it, due to
        flags being combined with various operators.

        @param container: The L{Flags} subclass this constant is part of.

        @param names: When a single-flag value is being initialized, a C{str}
            giving the name of that flag.  This is the case which happens when
            a L{Flags} subclass is being initialized and L{FlagConstant}
            instances from its body are being realized.  Otherwise, a C{set} of
            C{str} giving names of all the flags set on this L{FlagConstant}
            instance.  This is the case when two flags are combined using C{|},
            for example.
        """
        if isinstance(names, str):
            name = names
            names = set([names])
        elif len(names) == 1:
            (name,) = names
        else:
            name = "{" + ",".join(sorted(names)) + "}"
        _Constant._realize(self, container, name, value)
        self.value = value
        self.names = names

        Complete the initialization of this L{FlagConstant}.

        This implementation differs from other C{_realize} implementations in
        that a L{FlagConstant} may have several names which apply to it, due to
        flags being combined with various operators.

        @param container: The L{Flags} subclass this constant is part of.

        @param names: When a single-flag value is being initialized, a C{str}
            giving the name of that flag.  This is the case which happens when
            a L{Flags} subclass is being initialized and L{FlagConstant}
            instances from its body are being realized.  Otherwise, a C{set} of
            C{str} giving names of all the flags set on this L{FlagConstant}
            instance.  This is the case when two flags are combined using C{|},
            for example.
        
stackoverflow/venv/lib/python3.6/site-packages/constantly/_constants.py