public void assertIsNotNegativeIfPresent(Integer integer, String propertyName) {
        if (integer != null && integer < 0) {
            problemReporter.report(new Problem(this, String.format("%s must be non negative", propertyName)));
        }
    }
Asserts the integer is either null or non-negative, reporting to {@link ProblemReporter} with this context if it is.

@param integer      Value to assert on.
@param propertyName Name of property.
aws-java-sdk-stepfunctions/src/main/java/com/amazonaws/services/stepfunctions/builder/internal/validation/ValidationContext.java