public GenerateDataKeyRequest addEncryptionContextEntry(String key, String value) {
        if (null == this.encryptionContext) {
            this.encryptionContext = new com.amazonaws.internal.SdkInternalMap<String, String>();
        }
        if (this.encryptionContext.containsKey(key))
            throw new IllegalArgumentException("Duplicated keys (" + key.toString() + ") are provided.");
        this.encryptionContext.put(key, value);
        return this;
    }
Add a single EncryptionContext entry

@see GenerateDataKeyRequest#withEncryptionContext
@returns a reference to this object so that method calls can be chained together.
aws-java-sdk-kms/src/main/java/com/amazonaws/services/kms/model/GenerateDataKeyRequest.java