code: def add_dependency(self, depend):
          
          try:
              self._add_child(self.depends, self.depends_set, depend)
          except TypeError as e:
              e = e.args[0]
              if SCons.Util.is_List(e):
                  s = list(map(str, e))
              else:
                  s = str(e)
              raise SCons.Errors.UserError("attempted to add a non-Node dependency to %s:\n\t%s is a %s, not a Node" % (str(self), s, type(e)))
docs: Adds dependencies.