code: public static JsonPullParser newParser(InputStream is, String charsetName)
  			throws UnsupportedEncodingException {
  		if (is == null) {
  			throw new IllegalArgumentException("'is' must not be null.");
  		}
  
  		try {
  			final Charset charset = (charsetName == null) ? null : Charset.forName(charsetName);
  			return newParser(is, charset);
  		} catch (UnsupportedCharsetException e) {
  			throw new UnsupportedEncodingException(e.getCharsetName());
  		}
  	}
docs: Creates a new parser, using the given InputStream as its {@code JSON} feed.
  
  <p>
  Please call one of the {@code setSource(...)}'s before calling other methods.
  </p>
  
  @param is
  An InputStream serves as {@code JSON} feed. Cannot be null.
  @param charsetName
  The character set should be assumed in which in the stream are encoded. {@link #DEFAULT_CHARSET_NAME} is assumed if null is passed.
  @return {@link JsonPullParser}
  @throws UnsupportedEncodingException
  An unknown character set is specified.
  @throws IllegalArgumentException
  {@code null} has been passed in where not applicable.