src/main/java/org/fest/assertions/ImageAssert.java
public @NotNull ImageAssert hasSize(@NotNull Dimension expected) {
    isNotNull();
    checkNotNull(expected);
    Dimension actualDimension = new Dimension(actual.getWidth(), actual.getHeight());
    if (areEqual(actualDimension, expected)) {
      return this;
    }
    failWithMessage(customErrorMessage());
    throw comparisonFailed(rawDescription(), new DimensionFormatter(actualDimension), new DimensionFormatter(expected));
  }
public @NotNull ImageAssert hasSize(@NotNull Dimension expected) {
    isNotNull();
    checkNotNull(expected);
    Dimension actualDimension = new Dimension(actual.getWidth(), actual.getHeight());
    if (areEqual(actualDimension, expected)) {
      return this;
    }
    failWithMessage(customErrorMessage());
    throw comparisonFailed(rawDescription(), new DimensionFormatter(actualDimension), new DimensionFormatter(expected));
  }
Verifies that the size of the actual image is equal to the given one.

@param expected the expected size of the actual image.
@return this assertion object.
@throws AssertionError       if the actual image is {@code null}.
@throws NullPointerException if the given size is {@code null}.
@throws AssertionError       if the size of the actual image is not equal to the given one.