def serialize_to_xml_str(obj_pyxb, pretty=True, strip_prolog=False, xslt_url=None):
    """Serialize PyXB object to pretty printed XML ``str`` for display.

    Args:
      obj_pyxb: PyXB object
        PyXB object to serialize.

      pretty: bool
        False: Disable pretty print formatting. XML will not have line breaks.

      strip_prolog:
        True: remove any XML prolog (e.g., ``<?xml version="1.0" encoding="utf-8"?>``),
        from the resulting XML doc.

      xslt_url: str
        If specified, add a processing instruction to the XML doc that specifies the
        download location for an XSLT stylesheet.

    Returns:
      str: Pretty printed XML document

    """
    return serialize_gen(obj_pyxb, None, pretty, strip_prolog, xslt_url)