new_contents: import logging
  from lxml import etree
  
  from pyven.exceptions.parser_exception import ParserException
  from pyven.parser.elements_parser import ElementsParser
  
  logger = logging.getLogger('global')
  
  class ConstantsParser(ElementsParser):
  
  	def __init__(self, query):
  		super(ConstantsParser, self).__init__(query)
  		
  	def parse(self, tree):
  		constants = {}
  		for node in tree.xpath(self.query):
  			try:
  				name = node.get('name')
  				if name is None:
  					raise ParserException('Missing constant name')
  				if name in constants.keys():
  					raise ParserException('Constant already declared : ' + name)
  				constants[name] = node.text
  			except ParserException as e:
  				raise e
  		return constants
subject: fix (constants) : added parentheses to constants