code: def test_print_schema(self):
      t = self.t_env.from_elements(
          [(1, "Hi", "Hello")], ["a", "b", "c"]
      )
      result = t.group_by(t.c).select(t.a.sum, t.c.alias("b"))
      result.print_schema()
  
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 1 for calling the StreamTableSchemaTests obj's underlying member method code with example usage: obj.test_print_schema() without return types