splitIntoPropertySelections () {
    const fragments = this.getFragments()
    return fragments.filter(f => f instanceof Selection.Fragment).map(f => {
      return new PropertySelection(f.path, f.startOffset,
        f.endOffset, false, this.containerPath, this.surfaceId)
    })
  }
Splits a container selection into property selections.

@returns {PropertySelection[]}