content: import pytest
  
  from web3._utils.blocks import (
      is_predefined_block_number,
  )
  
  
  @pytest.mark.parametrize(
      "block_identifier,expected",
      (
          ("earliest", True),
          ("latest", True),
          ("finalized", True),
          ("safe", True),
          ("pending", True),
          (1, False),
          ("0x1", False),
      ),
  )
  def test_is_predefined_block_number(block_identifier, expected):
      actual = is_predefined_block_number(block_identifier)
      assert actual is expected
  