dap4/d4cdm/src/main/java/dap4/cdm/nc2/DapNetcdfFile.java
@Override
    public List<Array>
    readArrays(List<Variable> variables)
            throws IOException
    {
        List<Array> result = new ArrayList<Array>();
        for(Variable variable : variables) {
            result.add(variable.read());
        }
        return result;
    }
@Override
    public List<Array>
    readArrays(List<Variable> variables)
            throws IOException
    {
        List<Array> result = new ArrayList<Array>();
        for(Variable variable : variables) {
            result.add(variable.read());
        }
        return result;
    }
Do a bulk read on a list of Variables and
return a corresponding list of Array that contains the results
of a full read on each Variable.
TODO: optimize to make only a single server call and cache the results.

@param variables List of type Variable
@return List of Array, one for each Variable in the input.
@throws IOException if read error