code: public static void addParameter(final Map<String, String[]> parameters, final String name, final String value) {
  		if (parameters.containsKey(name)) {
  			// This field contains multiple values, append the new value to the existing values.
  			String[] oldValues = parameters.get(name);
  			String[] newValues = new String[oldValues.length + 1];
  			System.arraycopy(oldValues, 0, newValues, 0, oldValues.length);
  			newValues[newValues.length - 1] = value;
  			parameters.put(name, newValues);
  		} else {
  			parameters.put(name, new String[]{value});
  		}
  	}
docs: Add the request parameter to the parameters collection. If a parameter already exists with the given name then
  the Map will contain an array of all registered values.
  
  @param parameters the map to store non-file request parameters in.
  @param name the name of the parameter.
  @param value the parameter value.