text: # A set of regression tests for open issues
  
  import cocotb
  from cocotb.triggers import Timer
  
  
  async def toggle_clock(dut):
      dut.clk.value = 0
      await Timer(10, "ns")
      assert dut.clk.value.integer == 0, "Clock not set to 0 as expected"
      dut.clk.value = 1
      await Timer(10, "ns")
      assert dut.clk.value.integer == 1, "Clock not set to 1 as expected"
  
  
  @cocotb.test()
  async def issue_253_empty(dut):
      await toggle_clock(dut)
  
  
  @cocotb.test()
  async def issue_253_none(dut):
      await toggle_clock(dut)
  
  
  @cocotb.test()
  async def issue_253_notset(dut):
      await toggle_clock(dut)
  