WidgetEnum:
| "CATEGORIZER"
| "CS_PROGRAM"
| "DEFINITION"
| "DEPRECATED_STANDIN"
| "DROPDOWN"
| "EXPLANATION"
| "EXPRESSION"
| "FREE_RESPONSE"
| "GRADED_GROUP"
| "GRADED_GROUP_SET"
| "GRAPHER"
| "GROUP"
| "IFRAME"
| "IMAGE"
| "INPUT_NUMBER"
| "INTERACTIVE"
| "INTERACTIVE_GRAPH"
| "LABEL_IMAGE"
| "LIGHTS_PUZZLE"
| "MATCHER"
| "MATRIX"
| "MEASURER"
| "MOLECULE"
| "NUMBER_LINE"
| "NUMERIC_INPUT"
| "ORDERER"
| "PASSAGE"
| "PASSAGE_REF"
| "PASSAGE_REF_TARGET"
| "PHET_SIMULATION"
| "PLOTTER"
| "PYTHON_PROGRAM"
| "REACTION_DIAGRAM"
| "RADIO"
| "SEQUENCE"
| "SIMULATOR"
| "SORTER"
| "TABLE"
| "UNIT"
| "VIDEO"