docs/doc/reference/com/google/android/exoplayer2/upstream/CmcdConfiguration.HeaderKey.html
Package com.google.android.exoplayer2.upstream
[@Retention](https://developer.android.com/reference/java/lang/annotation/Retention.html "class or interface in java.lang.annotation")([SOURCE](https://developer.android.com/reference/java/lang/annotation/RetentionPolicy.html?is-external=true#SOURCE "class or interface in java.lang.annotation"))[@Documented](https://developer.android.com/reference/java/lang/annotation/Documented.html "class or interface in java.lang.annotation")[@Target](https://developer.android.com/reference/java/lang/annotation/Target.html "class or interface in java.lang.annotation")([TYPE\_USE](https://developer.android.com/reference/java/lang/annotation/ElementType.html?is-external=true#TYPE_USE "class or interface in java.lang.annotation"))
public static @interfaceCmcdConfiguration.HeaderKey
Header keys SHOULD be allocated to one of the four defined header names based upon their expected level of variability: