question: public void validateEmrClusterDefinitionKey ( EmrClusterDefinitionKey key ) throws IllegalArgumentException { Assert . notNull ( key , "An EMR cluster definition key must be specified." ) ; key . setNamespace ( alternateKeyHelper . validateStringParameter ( "namespace" , key . getNamespace ( ) ) ) ; key . setEmrClusterDefinitionName ( alternateKeyHelper . validateStringParameter ( "An" , "EMR cluster definition name" , key . getEmrClusterDefinitionName ( ) ) ) ; }
target:  Validates the EMR cluster definition key. This method also trims the key parameters.