presto-spi/src/main/java/io/prestosql/spi/security/PrestoPrincipal.java/PrestoPrincipal/PrestoPrincipal
class PrestoPrincipal:    @JsonCreator
    public PrestoPrincipal(@JsonProperty("type") PrincipalType type, @JsonProperty("name") String name)
    {
        this.type = requireNonNull(type, "type is null");
        this.name = requireNonNull(name, "name is null").toLowerCase(ENGLISH);
    }