code: def conductivity_prior_mean_5d(x):
      """Prior mean for the conductivity."""
      vol1 = x[0]  # Na2SO4
      vol2 = x[1]  # NaNO3
      vol3 = x[2]  # LiNO3
      vol4 = x[3]  # Li2SO4
      vol5 = x[4]  # NaClO4
      vol6 = 10 - (vol1 + vol2 + vol3 + vol4 + vol5)  # Water
      # Synthetic functions
      return (
          1.01 * (vol1 + vol5)
          + 0.15 * (vol2 + vol3) ** 2.05
          + 0.76 * vol4 * vol3
          + 2.2 * vol6 * (vol1**1.6)
      )
  
label_desc: Use image node_id 3 for calling a global function with example usage: conductivity_prior_mean_5d(x) and returns: unknown