code: def test__accept_true():
      """Check valid prefix"""
      # Arrange
      prefix = b"DDS etc"
  
      # Act
      output = DdsImagePlugin._accept(prefix)
  
      # Assert
      assert output
  
imports: from io import BytesIO
  import pytest
  from PIL import DdsImagePlugin, Image
  from .helper import assert_image_equal, assert_image_equal_tofile, hopper
label_desc: Use image node_id 11 for calling a global function with example usage: test__accept_true() without return types