LengthOf (checker-framework 3.39.0-eisop1 API)

```
@Documented
@Retention(RUNTIME)
@Target({TYPE_USE,TYPE_PARAMETER,METHOD})
public @interface LengthOf
```
An integer that, for each of the given sequences, is equal to the sequence's length.
This is treated as an IndexOrHigh annotation internally. This is an implementation detail that may change in the future, when this type may be used to implement more precise refinements.
The usual use case for the LengthOf annotation is in the defintions of custom collections. Consider the signature of java.lang.String#length():
```
     public @LengthOf("this") int length()
 
```
See the Checker Framework Manual:
Index Checker

- Required Element Summary
  
  Required Elements
  Modifier and Type Required Element Description
  
  java.lang.String[] value
  Sequences that the annotated expression is equal to the length of.

- Element Detail
  - value
```
java.lang.String[] value
```
    Sequences that the annotated expression is equal to the length of.