def builder_support(builder):
    """
    Return True when builder is supported.

    Supported builders output in html format, but exclude
    `PickleHTMLBuilder` and `JSONHTMLBuilder`, which run into issues
    when serializing blog objects.
    """

    if hasattr(builder, "builder"):
        builder = builder.builder

    not_supported = {"json", "pickle"}
    return builder.format == "html" and builder.name not in not_supported