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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 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)