public GetRecoveryPointRestoreMetadataResult addRestoreMetadataEntry(String key, String value) {
        if (null == this.restoreMetadata) {
            this.restoreMetadata = new java.util.HashMap<String, String>();
        }
        if (this.restoreMetadata.containsKey(key))
            throw new IllegalArgumentException("Duplicated keys (" + key.toString() + ") are provided.");
        this.restoreMetadata.put(key, value);
        return this;
    }
Add a single RestoreMetadata entry

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