Type check this object.

def check(self):
    """
      Type check this object.
    """
    try:
      si, uninterp = self.interpolate()
    # TODO(wickman) This should probably be pushed out to the interpolate leaves.
    except (Object.CoercionError, MustacheParser.Uninterpolatable) as e:
      return TypeCheck(False, "Unable to interpolate: %s" % e)
    return self.checker(si)