code: def create_namespace(self, name, ignore_errors=False):
          
          if not self.has_namespace(name):
              self.namespaces[name] = ConjunctiveGraph()
              return True
          elif ignore_errors:
              return True
          else:
              raise RuntimeError("namespace '%s' already exists" % name)
docs: creates a namespace if it does not exist
  
          args:
              name: the name of the namespace
              ignore_errors(bool): Will ignore if a namespace already exists or
                      there is an error creating the namespace
  
          returns:
              True if created
              False if not created
              error if namespace already exists