public NumberExpression<T> ceil() {
        if (ceil == null) {
            ceil = Expressions.numberOperation(getType(), MathOps.CEIL, mixin);
        }
        return ceil;
    }
Create a {@code ceil(this)} expression

<p>Returns the smallest (closest to negative infinity)
{@code double} value that is greater than or equal to the
argument and is equal to a mathematical integer</p>

@return ceil(this)
@see java.lang.Math#ceil(double)
querydsl-core/src/main/java/com/querydsl/core/types/dsl/NumberExpression.java