cdm/src/main/java/ucar/nc2/dataset/VerticalCT.java
public VerticalTransform makeVerticalTransform(NetcdfDataset ds, Dimension timeDim) {
    return builder.makeMathTransform(ds, timeDim, this);
  }
public VerticalTransform makeVerticalTransform(NetcdfDataset ds, Dimension timeDim) {
    return builder.makeMathTransform(ds, timeDim, this);
  }
Use the builder to make the Vertical Transform function

@param ds      containing dataset
@param timeDim time Dimension
@return VerticalTransform
@see VertTransformBuilderIF#makeMathTransform