protected Integer resolveStringMinLength(MemberScope<?, ?> member) {
        if (member.getType().isInstanceOf(CharSequence.class)) {
            Size sizeAnnotation = this.getAnnotationFromFieldOrGetter(member, Size.class, Size::groups);
            if (sizeAnnotation != null && sizeAnnotation.min() > 0) {
                // minimum length greater than the default 0 was specified
                return sizeAnnotation.min();
            }
            if (this.getAnnotationFromFieldOrGetter(member, NotEmpty.class, NotEmpty::groups) != null
                    || this.getAnnotationFromFieldOrGetter(member, NotBlank.class, NotBlank::groups) != null) {
                return 1;
            }
        }
        return null;
    }
Determine a given text type's minimum number of characters.

@param member the field or method to check
@return specified minimum number of characters (or null)
@see Size
@see NotEmpty
@see NotBlank
jsonschema-module-javax-validation/src/main/java/com/github/victools/jsonschema/module/javax/validation/JavaxValidationModule.java