validTestCaseAssertField = function (field, testCase) {
    const expectedValue = testCase.value;
    assert.deepEqual(field.getValue(), expectedValue);
    assert.equal(field.getImageHeight(), expectedValue.length);
    assert.equal(field.getImageWidth(), expectedValue[0].length);
  }
Asserts that the field properties are correct based on the test case.
@param {FieldBitmap} field The field to check.
@param {FieldValueTestCase} testCase The test case.