add comments for _extends/graph_kernel/_init_.py

src/mindspore2022/mindspore/python/mindspore/_extends/graph_kernel/__init__.py

@@ -13,6 +13,9 @@
 # limitations under the License.
 # ============================================================================
 """init"""
+# 从splitter模块中导入split_with_json函数
 from .splitter import split_with_json
+# 从expander模块中导入get_op_expander函数
 from .expander import get_op_expander
+# 从parallel_estimate模块中导入estimate_calculation_amount和estimate_ops函数
 from .parallel_estimate import estimate_calculation_amount, estimate_ops