Priority for extractors

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #107 
| License       | MIT
| Doc PR        | need to be written
well, but normally you will add several extractors and then extract once. the ChainRouter actually caches the sorted list, which is the most performant operation if several calls are expected.