docs: def rmsd_eval(cls, specification, sequences, parameters, reference_ampal,
                    **kwargs):
          """Creates optimizer with default build and RMSD eval.
  
          Notes
          -----
          Any keyword arguments will be propagated down to BaseOptimizer.
  
          RMSD eval is restricted to a single core only, due to restrictions
          on closure pickling.
  
          Parameters
          ----------
          specification : ampal.assembly.specification
              Any assembly level specification.
          sequences : [str]
              A list of sequences, one for each polymer.
          parameters : [base_ev_opt.Parameter]
              A list of `Parameter` objects in the same order as the
              function signature expects.
          reference_ampal : ampal.Assembly
              The target structure of the optimisation.
          """
          eval_fn = make_rmsd_eval(reference_ampal)
          instance = cls(specification,
                         sequences,
                         parameters,
                         build_fn=default_build,
                         eval_fn=eval_fn,
                         mp_disabled=True,
                         **kwargs)
          return instance