code: def properties_dict_for(self, index):
          
          props = self.properties_for(index)
          prop_index = extract_properties_to_index(index, props)
          return prop_index
docs: Return a dictionary, containing properties as keys and indices as index
          Thus, the indices for each constraint, which is contained will be collected as
          one dictionary
  
          Example:
          let properties: 'one':[1,2,3,4], 'two':[3,5,6]
  
          >>> properties_dict_for([2,3,5])
          {'one':[2,3], 'two':[3,5]}