public JibContainerBuilder addFileEntriesLayer(FileEntriesLayer layer) {
    containerBuildPlanBuilder.addLayer(layer);
    layerConfigurations.add(layer);
    return this;
  }
Adds a layer (defined by a {@link FileEntriesLayer}).

@param layer the {@link FileEntriesLayer}
@return this
jib-core/src/main/java/com/google/cloud/tools/jib/api/JibContainerBuilder.java