code: def parse_constant(self, node):
          
  
          try:
              name = node.lattrib['name']
          except:
              self.raise_error('<Constant> must specify a name.')
  
          dimension = node.lattrib.get('dimension', None)
  
          try:
              value = node.lattrib['value']
          except:
              self.raise_error("Constant '{0}' must have a value.", name)
  
          description = node.lattrib.get('description', '')
  
          constant = Constant(name, value, dimension, description)
  
          if self.current_component_type:
              self.current_component_type.add_constant(constant)
          else:
              self.model.add_constant(constant)
docs: Parses <Constant>
  
          @param node: Node containing the <Constant> element
          @type node: xml.etree.Element