canExpand (annos, sel) {
    // When there's some overlap with only a single annotation we do an expand
    if (annos.length !== 1) return false
    const annoSel = annos[0].getSelection()
    return sel.overlaps(annoSel, 'strict') && !sel.isInsideOf(annoSel)
  }
Checks if annotation could be expanded.
    There should be overlap with only a single annotation,
    selection should be also outside of this annotation.

    @param {Array} annos annotations
    @param {Object} sel selection

    @returns {Boolean} Whether or not annotation could be expanded.