dap4/d4cdm/src/main/java/dap4/cdm/nc2/DMRToCDM.java
public NodeMap<CDMNode,DapNode>
    create()
            throws DapException
    {
        // Netcdf Dataset will already have a root group
        Group cdmroot = ncfile.getRootGroup();
        this.nodemap.put(cdmroot,this.dmr);
        fillGroup(cdmroot, this.dmr, ncfile);
        return this.nodemap;
    }
public NodeMap<CDMNode,DapNode>
    create()
            throws DapException
    {
        // Netcdf Dataset will already have a root group
        Group cdmroot = ncfile.getRootGroup();
        this.nodemap.put(cdmroot,this.dmr);
        fillGroup(cdmroot, this.dmr, ncfile);
        return this.nodemap;
    }
Do the conversion and return a NodeMap
representing the conversion.

@throws DapException