code: def test_get_schema(self):
      t = self.t_env.from_elements(
          [(1, "Hi", "Hello")], ["a", "b", "c"]
      )
      result = t.group_by(t.c).select(
          t.a.sum.alias("a"), t.c.alias("b")
      )
      schema = result.get_schema()
  
      assert schema == TableSchema(
          ["a", "b"], [DataTypes.BIGINT(), DataTypes.STRING()]
      )
  
imports: from pyflink.table.table_schema import TableSchema
  from pyflink.table.types import DataTypes
  from pyflink.testing.test_case_utils import PyFlinkStreamTableTestCase
label_desc: Use image node_id 2 for calling the StreamTableSchemaTests obj's underlying member method code with example usage: obj.test_get_schema() without return types