code: def test_basic_format_safety(self):
      env = SandboxedEnvironment()
      t = env.from_string(
          '{{ "a{x.__class__}b".format_map({"x":42}) }}'
      )
      assert t.render() == "ab"
  
imports: import pytest
  from jinja2 import Environment
  from jinja2 import escape
  from jinja2 import Markup
  from jinja2._compat import text_type
  from jinja2.exceptions import SecurityError
  from jinja2.exceptions import TemplateRuntimeError
  from jinja2.exceptions import TemplateSyntaxError
  from jinja2.nodes import EvalContext
  from jinja2.sandbox import ImmutableSandboxedEnvironment
  from jinja2.sandbox import SandboxedEnvironment
  from jinja2.sandbox import unsafe
label_desc: Use image node_id 1 for calling the TestStringFormatMap obj's underlying member method code with example usage: obj.test_basic_format_safety() without return types