server/src/main/java/org/elasticsearch/index/mapper/vectors/DenseVectorFieldMapper.java
public static final String CONTENT_TYPE = "dense_vector";
    public static short MAX_DIMS_COUNT = 2048; 
    public static final int MAGNITUDE_BYTES = 4;
    private static DenseVectorFieldMapper toType(FieldMapper in) {
        return (DenseVectorFieldMapper) in;
    }
    public static class Builder extends FieldMapper.Builder {
        private final Parameter<ElementType> elementType = new Parameter<>("element_type", false, () -> ElementType.FLOAT, (n, c, o) -> {
            ElementType elementType = namesToElementType.get((String) o);
            if (elementType == null) {
                throw new MapperParsingException("invalid element_type [" + o + "]; available types are " + namesToElementType.keySet());
            }
            return elementType;
        }, m -> toType(m).elementType, XContentBuilder::field, Objects::toString);
        private final Parameter<Integer> dims = new Parameter<>(
            "dims",
            false,
            () -> null,
            (n, c, o) -> XContentMapValues.nodeIntegerValue(o),
            m -> toType(m).dims,
            XContentBuilder::field,
            Objects::toString
        ).addValidator(dims -> {
            if (dims == null) {
                throw new MapperParsingException("Missing required parameter [dims] for field [" + name + "]");
            }
            if ((dims > MAX_DIMS_COUNT) || (dims < 1)) {
                throw new MapperParsingException(
                    "The number of dimensions for field ["
                        + name