docs: def parse_case(self, node):
          """
          Parses <Case>
  
          @param node: Node containing the <Case> element
          @type node: xml.etree.Element
  
          @raise ParseError: When no condition or value is specified
          """
          
          try:
              condition = node.lattrib['condition']
          except:
              condition = None
              
          try:
              value = node.lattrib['value']
          except:
              self.raise_error('<Case> must specify a value')
  
          self.current_conditional_derived_variable.add_case(Case(condition, value))