src/draw.js
/**
  * An monotonically increasing id generator
  *
  * @param object string prefix
  * @return none
  */
An monotonically increasing id generator
@param object string prefix
@return none
An monotonically increasing id generator @param object string prefix @return none
* genID(s) {
    let idx = 0;
    while (true)
      yield {str:s + `_i-${idx}`, idx:idx++};
  }
* genID ( s ) { let idx = 0 ; while ( true ) yield { str : s + ` ${ idx } ` , idx : idx ++ } ; }
An monotonically increasing id generator
 @param object string prefix
 @return none
An monotonically increasing id generator @param object string prefix @return none