public static <T> T checkNotNull(T reference,
                                   String errorMessageTemplate,
                                   Object... errorMessageArgs) {
    if (reference == null) {
      // If either of these parameters is null, the right thing happens anyway
      throw new NullPointerException(
          format(errorMessageTemplate, errorMessageArgs));
    }
    return reference;
  }
Ensures that an object reference passed as a parameter to the calling
method is not null.

@param reference an object reference
@param errorMessageTemplate a template for the exception message should the
    check fail. The message is formed by replacing each {@code %s}
    placeholder in the template with an argument. These are matched by
    position - the first {@code %s} gets {@code errorMessageArgs[0]}, etc.
    Unmatched arguments will be appended to the formatted message in square
    braces. Unmatched placeholders will be left as-is.
@param errorMessageArgs the arguments to be substituted into the message
    template. Arguments are converted to strings using
    {@link String#valueOf(Object)}.
@return the non-null reference that was validated
@throws NullPointerException if {@code reference} is null
selendroid-server/src/main/java/io/selendroid/server/util/Preconditions.java