code: def check_duplicate_options(self, section1, section2, raise_error=False):
          
          # Sanity checking
          if not self.has_section(section1):
              raise ValueError('Section %s not present in ConfigParser.'\
                               %(section1,) )
          if not self.has_section(section2):
              raise ValueError('Section %s not present in ConfigParser.'\
                               %(section2,) )
  
          items1 = self.options(section1)
          items2 = self.options(section2)
  
          # The list comprehension here creates a list of all duplicate items
          duplicates = [x for x in items1 if x in items2]
  
          if duplicates and raise_error:
              raise ValueError('The following options appear in both section ' +\
                               '%s and %s: %s' \
                               %(section1,section2,' '.join(duplicates)))
  
          return duplicates
docs: Check for duplicate options in two sections, section1 and section2.
          Will return a list of the duplicate options.
  
          Parameters
          ----------
          section1 : string
              The name of the first section to compare
          section2 : string
              The name of the second section to compare
          raise_error : Boolean, optional (default=False)
              If True, raise an error if duplicates are present.
  
          Returns
          ----------
          duplicates : List
              List of duplicate options