code: public final void setDialogPreviewShape(@NonNull final PreviewShape previewShape) {
          Condition.INSTANCE.ensureNotNull(previewShape, "The preview shape may not be null");
          this.dialogPreviewShape = previewShape;
      }
docs: Sets the shape, which should be used to preview colors in the preference's dialog.
  
  @param previewShape
  The shape, which should be set, as a value of the enum {@link PreviewShape}. The
  shape may not be null