collectPool() {
    let host = this.root.host;
    let pool=[], i=0;
    for (let n=host.firstChild; n; n=n.nextSibling) {
      pool[i++] = n;
    }
    return pool;
  }
// these with the "content root" to arrive at the composed tree.
these with the "content root" to arrive at the composed tree.
these with the " content root " to arrive at the composed tree .
collectPool() {
    let host = this.root.host;
    let pool=[], i=0;
    for (let n=host.firstChild; n; n=n.nextSibling) {
      pool[i++] = n;
    }
    return pool;
  }
collectPool ( ) { let host = this . root . host ; let pool = [ ] , i = 0 ; for ( let n = host . firstChild ; n ; n = n . nextSibling ) { pool [ i ++ ] = n ; } return pool ; }
these with the "content root" to arrive at the composed tree.
these with the " content root " to arrive at the composed tree .