Example:

```js
        function Example(props) {
          useEffect(() => {
            let topHeight = 0;
            topHeight = props.upperViewHeight;
          }, [props.upperViewHeight]);
        }
```

This is **not** supposed to violate because `props.upperViewHeight` is in the deps.
deps.size > 1 ? 'them' : 'it'
          } or remove the dependency array.`
        );
      }
      let extraWarning = '';
      if (unnecessaryDependencies.size > 0) {
        let badRef = null;
        Array.from(unnecessaryDependencies.keys()).forEach(key => {
          if (badRef !== null) {
            return;
          }
          if (key.endsWith('.current')) {
            badRef = key;
          }
        });
        if (badRef !== null) {
          extraWarning =
            ` Mutable values like '${badRef}' aren't valid dependencies ` +
            "because mutating them doesn't re-render the component.";
        } else if (externalDependencies.size > 0) {
          const dep = Array.from(externalDependencies)[0];
          
          
          if (!scope.set.has(dep)) {
            extraWarning =
              ` Outer scope values like '${dep}' aren't valid dependencies ` +
              `because mutating them doesn't re-render the component.`;
          }
        }
      }