code: public NewChunk asciiToLower(NewChunk nc) {
      // copy existing data
      nc = this.extractRows(nc, 0,_len);
      //update offsets and byte array
      for(int i= 0; i < nc._sslen; i++) {
        if (nc._ss[i] > 0x40 && nc._ss[i] < 0x5B) // check for capital letter
          nc._ss[i] += 0x20; // lower it
      }
  
      return nc;
    }
docs: Optimized toLower() method to operate across the entire CStrChunk buffer in one pass.
  This method only changes the values of ASCII uppercase letters in the text.
  
  NewChunk is the same size as the original.
  
  @param nc NewChunk to be filled with the toLower version of ASCII strings in this chunk
  @return Filled NewChunk