PlacementContext (Solr 9.9.0 core API)

All Known Implementing Classes:

SimplePlacementContextImpl
```
public interface PlacementContext
```
Placement context makes it easier to pass around and access main placement-related components.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`AttributeFetcher`	`getAttributeFetcher()`	Factory used by the plugin to fetch additional attributes from the cluster nodes, such as count of cores, system properties etc..
`BalancePlanFactory`	`getBalancePlanFactory()`	Factory used to create instances of `BalancePlan` to return computed decision.
`Cluster`	`getCluster()`	Initial state of the cluster.
`PlacementPlanFactory`	`getPlacementPlanFactory()`	Factory used to create instances of `PlacementPlan` to return computed decision.

- Method Detail
  - getCluster
```
Cluster getCluster()
```
    Initial state of the cluster. Note there are Set's and Map's accessible from the Cluster and other reachable instances. These collection will not change while the plugin is executing and will be thrown away once the plugin is done. The plugin code can therefore modify them if needed.
  - getAttributeFetcher
```
AttributeFetcher getAttributeFetcher()
```
    Factory used by the plugin to fetch additional attributes from the cluster nodes, such as count of cores, system properties etc..
  - getPlacementPlanFactory
```
PlacementPlanFactory getPlacementPlanFactory()
```
    Factory used to create instances of PlacementPlan to return computed decision.
  - getBalancePlanFactory
```
BalancePlanFactory getBalancePlanFactory()
```
    Factory used to create instances of BalancePlan to return computed decision.