docs: def cmbuild_from_file(stockholm_file_path, refine=False,return_alignment=False,\
      params=None):
      """Uses cmbuild to build a CM file given a stockholm file.
  
          - stockholm_file_path: a path to a stockholm file.  This file should
              contain a multiple sequence alignment formated in Stockholm format.
              This must contain a sequence structure line:
                  #=GC SS_cons <structure string>
          - refine: refine the alignment and realign before building the cm.
              (Default=False)
          - return_alignment: Return alignment and structure string used to
              construct the CM file.  This will either be the original alignment
              and structure string passed in, or the refined alignment if
              --refine was used. (Default=False)
      """
      #get alignment and structure string from stockholm file.
      info, aln, structure_string = \
          list(MinimalRfamParser(open(stockholm_file_path,'U'),\
              seq_constructor=ChangedSequence))[0]
  
      #call cmbuild_from_alignment.
      res = cmbuild_from_alignment(aln, structure_string, refine=refine, \
          return_alignment=return_alignment,params=params)
      return res