guava/src/com/google/common/base/Preconditions.java
@CanIgnoreReturnValue
  public static <T extends @NonNull Object> T checkNotNull(
      T obj, @Nullable String errorMessageTemplate, char p1) {
    if (obj == null) {
      throw new NullPointerException(lenientFormat(errorMessageTemplate, p1));
    }
    return obj;
  }
@CanIgnoreReturnValue
  public static <T extends @NonNull Object> T checkNotNull(
      T obj, @Nullable String errorMessageTemplate, char p1) {
    if (obj == null) {
      throw new NullPointerException(lenientFormat(errorMessageTemplate, p1));
    }
    return obj;
  }
Ensures that an object reference passed as a parameter to the calling method is not null.

<p>See {@link #checkNotNull(Object, String, Object...)} for details.

@since 20.0 (varargs overload since 2.0)