docs: def parse_objective_coefficient(entry):
      """Return objective value for reaction entry.
  
      Detect objectives that are specified using the non-standardized
      kinetic law parameters which are used by many pre-FBC SBML models. The
      objective coefficient is returned for the given reaction, or None if
      undefined.
  
      Args:
          entry: :class:`SBMLReactionEntry`.
      """
      for parameter in entry.kinetic_law_reaction_parameters:
          pid, name, value, units = parameter
          if (pid == 'OBJECTIVE_COEFFICIENT' or
                  name == 'OBJECTIVE_COEFFICIENT'):
              return value
  
      return None