docs: def _conglomerate_meshes(meshin, header):
      """Conglomerate meshes from several cores into one."""
      meshout = {}
      npc = header['nts'] // header['ncs']
      shp = [val + 1 if val != 1 else 1 for val in header['nts']]
      x_p = int(shp[0] != 1)
      y_p = int(shp[1] != 1)
      for coord in meshin[0]:
          meshout[coord] = np.zeros(shp)
      for icore in range(np.prod(header['ncs'])):
          ifs = [icore // np.prod(header['ncs'][:i]) % header['ncs'][i] * npc[i]
                 for i in range(3)]
          for coord, mesh in meshin[icore].items():
              meshout[coord][ifs[0]:ifs[0] + npc[0] + x_p,
                             ifs[1]:ifs[1] + npc[1] + y_p,
                             ifs[2]:ifs[2] + npc[2] + 1] = mesh
      return meshout