public StringExpression lower() {
        if (lower == null) {
            lower = Expressions.stringOperation(Ops.LOWER, mixin);
        }
        return lower;
    }
Create a {@code this.toLowerCase()} expression

<p>Get the lower case form</p>

@return this.toLowerCase()
@see java.lang.String#toLowerCase()
querydsl-core/src/main/java/com/querydsl/core/types/dsl/StringExpression.java