add valid_mandatory to parse_args

tiramisu_cmdline_parser.py

@@ -219,7 +219,10 @@ class TiramisuCmdlineParser(ArgumentParser):
             group.add_argument(*args, **kwargs)
 
 
-    def parse_args(self, *args, **kwargs):
+    def parse_args(self,
+                   *args,
+                   valid_mandatory=True,
+                   **kwargs):
         kwargs['namespace'] = TiramisuNamespace(self.config)
         try:
             namespaces = super().parse_args(*args, **kwargs)
@@ -236,6 +239,7 @@ class TiramisuCmdlineParser(ArgumentParser):
                 self.error('the following arguments are required: {}'.format(name))
             else:
                 self.error('unrecognized arguments: {}'.format(name))
+        if valid_mandatory:
             for key in self.config.value.mandatory():
                 if self.fullpath or '.' not in key:
                     name = key