public RawData setData(byte[] data) {
        if (data == null) {
            throw new IllegalArgumentException("Data can not be null.");
        }
        this.data = data;
        return this;
    }
Sets the byte array that constitutes this data. This does <b>not</b> copy the given array, it simply assigns
it to this.

@param data the data to set
@return this, to allow chaining
searchlib/src/main/java/com/yahoo/searchlib/aggregation/RawData.java