how to set atomsymbols off in ballstick display in marvin?

i am using marvin 4.1.5. jchem api. while using the Molecule.toObject() api, what option in the fmt string should i use to turn off atom symbols in the display. The display type should be ballstick.

Currently, there is no image export option to turn off atom symbols. But we will implement it.

In next Marvin release (4.1.8), there will be an image export option to hide atom symbols.