private void validateCompatibleTypes(DataType d, FieldValue v) {
        if (!d.isValueCompatible(v)) {
            throw new IllegalArgumentException(
                    "Incompatible data types. Got " + v.getDataType()
                    + ", expected " + d);
        }
    }
Checks if another object is equal to this set.

@param o the object to check for equality with
@return true if o is an instance of WeightedSet and the two encapsulated Maps are equal, false otherwise
document/src/main/java/com/yahoo/document/datatypes/MapFieldValue.java