映射文档 No. 86/244 (#6054)

* Add api_difference

* 'Fix'

docs/guides/model_convert/convert_from_pytorch/api_difference/Tensor/torch.Tensor.is_signed.md

@@ -0,0 +1,19 @@
+## [ 组合替代实现 ]torch.Tensor.is_signed
+
+### [torch.Tensor.is_signed](https://pytorch.org/docs/stable/generated/torch.Tensor.is_signed.html#torch.Tensor.is_signed)
+
+```python
+torch.Tensor.is_signed()
+```
+
+Paddle 无此 API，需要组合实现。
+
+### 转写示例
+
+```python
+# Pytorch 写法
+y = x.is_signed()
+
+# Paddle 写法
+y = x.dtype not in [paddle.uint8]
+```

docs/guides/model_convert/convert_from_pytorch/api_difference/others/torch.testing.assert_close.md

@@ -0,0 +1,19 @@
+## [ 组合替代实现 ]torch.testing.assert_close
+
+### [torch.testing.assert_close](https://pytorch.org/docs/stable/testing.html?highlight=assert_close#torch.testing.assert_close)
+
+```python
+torch.testing.assert_close(actual, expected, *, allow_subclasses=True, rtol=None, atol=None, equal_nan=False, check_device=True, check_dtype=True, check_layout=True, check_stride=False, msg=None)
+```
+
+Paddle 无此 API，需要组合实现。
+
+### 转写示例
+
+```python
+# Pytorch 写法
+torch.testing.assert_close(actual, expected, rtol=rtol, atol=atol, equal_nan=True, msg='error messege')
+
+# Paddle 写法
+assert paddle.allclose(actual, expected, rtol=rtol, atol=atol, equal_nan=True).item(), 'error messege'
+```