public BlobEntity getByNaturalId(@NotNull String name, @NotNull String mimeType, @NotNull Long hash) {
        Preconditions.requireNonBlank(name, "name must be non-blank");
        Preconditions.requireNonBlank(mimeType, "mimeType must be non-blank");
        Objects.requireNonNull(hash, "hash must be non-null");
        return getSession().byNaturalId(BlobEntity.class)
                           .using("hash", hash)
                           .using("name", name)
                           .using("mimeType", mimeType)
                           .load();
    }
Delete by provided ID (nb: not name, its ID set when stored).

<p>Does not truly delete the file if there are other (i.e. deduplicated) references to this blob. In this case
the reference counter is decremented.
manager/api/jpa/src/main/java/io/apiman/manager/api/jpa/blobstore/BlobStoreRepository.java