constructor(glyphModelObject) {
    Object.assign(this, glyphModelObject);
  }
Construct a glyph model from the parsed glyph model object
@param {{ 
onRefs: [number, number][], 
onOffsets: [number, number][], offOffsets: [number, number][], 
offOnIndices: number[], onContourIndices: number[], 
xAlign: string[][], yAlign: string[][] }} glyphModelObject