old_contents: """HDL Macro declarations."""
  
  from . import (HDLObject)
  
  
  class HDLMacro(HDLObject):
      """Macro declaration."""
  
      def __init__(self, name, value):
          """Initialize."""
          self.name = name
          self.value = value
  
      def dumps(self):
          """Dump representation."""
          return '    CONST {}: {}'.format(self.name, self.value)
  
new_contents: """HDL Macro declarations."""
  
  from . import (HDLObject)
  
  
  class HDLMacro(HDLObject):
      """Macro declaration."""
  
      def __init__(self, name, value):
          """Initialize."""
          self.name = name
          self.value = value
  
      def dumps(self):
          """Dump representation."""
          return '    CONST {}: {}'.format(self.name, self.value)
  
  
  class HDLMacroValue(HDLObject):
      """Usage of macros as placeholders."""
  
      def __init__(self, name):
          """Initialize."""
          self.name = name
  
      def dumps(self):
          """Dump representation."""
          return self.name
  
subject: add macro usage