code: def look_before_you_leap(self):
          
          errors = []
  
          try:
              self.check_dependencies()
          except self.Error as exc:
              errors.append(str(exc))
  
          if self.has_db:
              try:
                  self.manager.db_connector.get_collection()
              except Exception as exc:
                  errors.append("""
                      ERROR while trying to connect to the MongoDB database:
                          Exception:
                              %s
                          Connector:
                              %s
                      """ % (exc, self.manager.db_connector))
  
          return "\n".join(errors)
docs: This method should be called before running the calculation to make
          sure that the most important requirements are satisfied.
  
          Return:
              List of strings with inconsistencies/errors.