Simple Example showing DJL Locale issues

DJLLocaleTest.java

import ai.djl.mxnet.engine.MxNDArray;
import ai.djl.mxnet.engine.MxNDManager;
import ai.djl.mxnet.engine.MxOpParams;
import ai.djl.ndarray.NDArray;
import ai.djl.ndarray.NDManager;

// Tested using the following dependencies:
// compile "ai.djl:api:0.4.0"
// compile "ai.djl.mxnet:mxnet-engine:0.4.0"
// compile "ai.djl.mxnet:mxnet-native-auto:1.6.0"
// The error occurs on a Linux machine if LC_NUMERIC=de_DE.UTF-8 (Tested on Linux Mint 19.3)
// If LC_NUMERIC is set to en_US.UTF-8 everything works as expected.
public class DJLLocaleTest {
    public static void main(final String[] args) {
        final NDManager manager = NDManager.newBaseManager();
        //This is the bug: The double gets turned into the String "0.7" which seems to be parsed into a double again
        //by the MxNet engine. I think the engine uses the German number locale and turns the string "0.7" into a 0, as it
        //stops parsing at the first illegal char, the ".". (This is just a guess)
        //prints:
        //ND: () gpu(0) float64
        //1.3
        System.out.println(manager.create(1.3).add(0.7));
        
        //This works as expected, as creating an NDArray as argument circumvents the String parsing.
        //prints
        //ND: (1) gpu(0) float64
        //[2.]
        System.out.println(manager.create(1.3).add(manager.create(new double[]{0.7})));

        //We can reproduce the error by passing the string into the engine manually:
        //ND: () gpu(0) float64
        //1.3
        System.out.println(addWithStringParam((MxNDArray) manager.create(1.3), (MxNDManager)manager, "0.7"));

        // If we pass a number string with a German number format, it also works fine.
        //prints:
        //ND: () gpu(0) float64
        //2.
        System.out.println(addWithStringParam((MxNDArray) manager.create(1.3), (MxNDManager)manager, "0,7"));

    }

    /**
     * This is copy-pasted and modified from MxNDArray.
     * It executes the addition in the same way as MxNDArray.add(Number) does internally.
     */
    public static NDArray addWithStringParam(final MxNDArray array, final MxNDManager manager, final String param) {
        MxOpParams params = new MxOpParams();
        params.add("scalar", param);
        return manager.invoke("_npi_add_scalar", array, params);
    }
}