code: public @NotNull DoubleAssert isLessThanOrEqualTo(double other) {
      if (compareTo(other) <= 0) {
        return this;
      }
      failIfCustomMessageIsSet();
      throw failure(unexpectedGreaterThan(actual, other));
    }
docs: Verifies that the actual {@code Double} is less or equal to the given one.
  
  @param other the given value.
  @return this assertion object.
  @throws AssertionError if the actual {@code Double} is not less than or equal to the given one.