dap4/d4cdm/src/main/java/dap4/cdm/dsp/CDMDSP.java
protected void
    recordVar(Variable cdm, DapVariable dap)
    {
        cdm = CDMUtil.unwrap(cdm);
        assert varmap.get(cdm) == null && varmap.get(dap) == null;
        varmap.put(cdm, dap);
    }
protected void
    recordVar(Variable cdm, DapVariable dap)
    {
        cdm = CDMUtil.unwrap(cdm);
        assert varmap.get(cdm) == null && varmap.get(dap) == null;
        varmap.put(cdm, dap);
    }
Track Variable <-> DapVariable