code: public WrappedByteBuffer putString(String v, Charset cs) {
          java.nio.ByteBuffer strBuf = cs.encode(v);
          _autoExpand(strBuf.limit());
          _buf.put(strBuf);
          return this;
      }
docs: Puts a string into the buffer at the current position, using the character set to encode the string as bytes.
  
  @param v
  the string
  @param cs
  the character set
  
  @return the buffer