docs: def enrich(self, column, projects):
          """ This method adds a new column named as 'project'
          that contains information about the associated project
          that the event in 'column' belongs to.
  
          :param column: column with information related to the project
          :type column: string
          :param projects: information about item - project
          :type projects: pandas.DataFrame
  
          :returns: original data frame with a new column named 'project'
          :rtype: pandas.DataFrame
          """
  
          if column not in self.data.columns:
              return self.data
  
          self.data = pandas.merge(self.data, projects, how='left', on=column)
  
          return self.data