docs: def align_two_alignments(aln1_fp, aln2_fp, moltype, params=None):
      """Returns an Alignment object from two existing Alignments.
  
      Parameters
      ----------
      aln1_fp : string
          file path of 1st alignment
      aln2_fp : string
          file path of 2nd alignment
      params : dict of parameters to pass in to the Mafft app controller.
  
      Returns
      -------
          The aligned sequences.
      """
  
      # Create Mafft app.
      app = Mafft(InputHandler='_input_as_paths',
                  params=params,
                  SuppressStderr=False)
      app._command = 'mafft-profile'
  
      # Get results using int_map as input to app
      res = app([aln1_fp, aln2_fp])
  
      return Alignment.read(res['StdOut'], constructor=moltype)