How to use the pythran.metadata function in pythran

def visit(self, node):
        # be aware of metadata
        md.visit(self, node)
        return super(ExtendedDefUseChains, self).visit(node)

def handle_omp_for(self, node, local_iter):
        """
        Fix OpenMP directives on For loops.

        Add the target as private variable as a new variable may have been
        introduce to handle cxx iterator.

        Also, add the iterator as shared variable as all 'parallel for chunck'
        have to use the same iterator.
        """
        for directive in metadata.get(node, OMPDirective):
            if any(key in directive.s for key in (' parallel ', ' task ')):
                # Eventually add local_iter in a shared clause as iterable is
                # shared in the for loop (for every clause with datasharing)
                directive.s += ' shared({})'
                directive.deps.append(ast.Name(local_iter, ast.Load(),
                                               None, None))
                directive.shared_deps.append(directive.deps[-1])

            target = node.target
            assert isinstance(target, ast.Name)
            hasfor = 'for' in directive.s
            nodefault = 'default' not in directive.s
            noindexref = all(isinstance(x, ast.Name) and
                             x.id != target.id for x in directive.deps)
            if (hasfor and nodefault and noindexref and
                    target.id not in self.scope[node]):