docs: public void setTarget(CharSequence text, int start, int len) {
          char[] mychars = data;
          if (mychars == null || shared || mychars.length < len) {
              data = mychars = new char[(int) (1.7f * len)];
              shared = false;
          }
          for (int i = start, p = 0; i < len; i++, p++) {
              mychars[p] = text.charAt(i);
          }
          //text.getChars(start, len, mychars, 0); //(srcBegin,srcEnd,dst[],dstBegin)
          offset = 0;
          end = len;
  
          cache = text;
          cacheOffset = -start;
          cacheLength = text.length();
  
          init();
      }