def validate_field(
    field,
    path=None,
    ftype=None,
    embedded_doc_type=None,
    subfield=None,
    read_only=None,
):
    """Validates that the field matches the given constraints.

    Args:
        field: a :class:`Field`
        path (None): the field or ``embedded.field.name``. Only used to
            generate more informative error messages
        ftype (None): an optional field type or iterable of types to enforce.
            Must be subclass(es) of :class:`Field`
        embedded_doc_type (None): an optional embedded document type or
            iterable of types to enforce. Must be subclass(es) of
            :class:`fiftyone.core.odm.BaseEmbeddedDocument`
        subfield (None): an optional subfield type or iterable of subfield
            types to enforce. Must be subclass(es) of :class:`Field`
        read_only (None): whether to optionally enforce that the field is
            read-only (True) or not read-only (False)

    Raises:
        ValueError: if the constraints are not valid
    """
    if ftype is None and embedded_doc_type is None and subfield is None:
        return

    if field is None:
        raise ValueError("%s does not exist" % _make_prefix(path))

    if ftype is not None:
        if etau.is_container(ftype):
            ftype = tuple(ftype)

        if not isinstance(field, ftype):
            raise ValueError(
                "%s has type %s, not %s"
                % (_make_prefix(path), type(field), ftype)
            )

    if embedded_doc_type is not None:
        if etau.is_container(embedded_doc_type):
            embedded_doc_type = tuple(embedded_doc_type)

        if not isinstance(field, EmbeddedDocumentField):
            raise ValueError(
                "%s has type %s, not %s"
                % (_make_prefix(path), type(field), EmbeddedDocumentField)
            )

        if not issubclass(field.document_type, embedded_doc_type):
            raise ValueError(
                "%s has document type %s, not %s"
                % (_make_prefix(path), field.document_type, embedded_doc_type)
            )

    if subfield is not None:
        if etau.is_container(subfield):
            subfield = tuple(subfield)

        if not isinstance(field, (ListField, DictField)):
            raise ValueError(
                "%s has type %s, not %s"
                % (_make_prefix(path), type(field), (ListField, DictField))
            )

        if not isinstance(field.field, subfield):
            raise ValueError(
                "%s has subfield type %s, not %s"
                % (_make_prefix(path), type(field.field), subfield)
            )

    if read_only is not None:
        if read_only != field.read_only:
            raise ValueError(
                "%s has read_only %s, not %s"
                % (_make_prefix(path), field.read_only, read_only)
            )
Validates that the field matches the given constraints.

    Args:
        field: a :class:`Field`
        path (None): the field or ``embedded.field.name``. Only used to
            generate more informative error messages
        ftype (None): an optional field type or iterable of types to enforce.
            Must be subclass(es) of :class:`Field`
        embedded_doc_type (None): an optional embedded document type or
            iterable of types to enforce. Must be subclass(es) of
            :class:`fiftyone.core.odm.BaseEmbeddedDocument`
        subfield (None): an optional subfield type or iterable of subfield
            types to enforce. Must be subclass(es) of :class:`Field`
        read_only (None): whether to optionally enforce that the field is
            read-only (True) or not read-only (False)

    Raises:
        ValueError: if the constraints are not valid
    
fiftyone/core/fields.py