Key

```
public class Key
extends Object
```
A Key is a unique identifier for a node in a quadtree. It contains a lower-left point and a level number. The level number is the power of two for the size of the node envelope

Constructor and Description
`Key(Envelope itemEnv)`

All Methods

Static Methods

Instance Methods

Concrete Methods
Modifier and Type	Method and Description
`void`	`computeKey(Envelope itemEnv)` return a square envelope containing the argument envelope, whose extent is a power of two and which is based at a power of 2
`static int`	`computeQuadLevel(Envelope env)`
`Coordinate`	`getCentre()`
`Envelope`	`getEnvelope()`
`int`	`getLevel()`
`Coordinate`	`getPoint()`

public static int computeQuadLevel(Envelope env)

computeKey
```
public void computeKey(Envelope itemEnv)
```
return a square envelope containing the argument envelope, whose extent is a power of two and which is based at a power of 2

Class Key