code: private void checkValueType(TemplateParam param, SoyValue value, TemplateNode node) {
      if (!TofuTypeChecks.isInstance(param.type(), value, node.getSourceLocation())) {
        // should this be a soydataexception?
        throw RenderException.createWithSource(
            "Parameter type mismatch: attempt to bind value '"
                + (value instanceof UndefinedData ? "(undefined)" : value)
                + "' (a "
                + value.getClass().getSimpleName()
                + ") to parameter '"
                + param.name()
                + "' which has a declared type of '"
                + param.type()
                + "'.",
            node);
      }
    }
docs: Check that the value matches the given param type.