code: public String findSymbolIfExists(char[] buffer, int start, int len, int hash)
      {
          // Sanity check:
          if (len < 1) {
              return EMPTY_STRING;
          }
          hash &= mIndexMask;
  
          String sym = mSymbols[hash];
          // Optimal case; checking existing primary symbol for hash index:
          if (sym != null) {
              // Let's inline primary String equality checking:
              if (sym.length() == len) {
                  int i = 0;
                  do {
                      if (sym.charAt(i) != buffer[start+i]) {
                          break;
                      }
                  } while (++i < len);
                  // Optimal case; primary match found
                  if (i == len) {
                      return sym;
                  }
              }
              // How about collision bucket?
              Bucket b = mBuckets[hash >> 1];
              if (b != null) {
                  sym = b.find(buffer, start, len);
                  if (sym != null) {
                      return sym;
                  }
              }
          }
          return null;
      }
docs: Similar to {link #findSymbol}, but will not add passed in symbol
  if it is not in symbol table yet.