# Functions
FormatMapToXML marshal map[string]string to xmlWriter with xml format, the root node name is xml.
ParseXMLToMap parses xml reading from xmlReader and returns the first-level sub-node key-value set, if the first-level sub-node contains child nodes, skip it.
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# Constants
ResultCodeFail fail.
ResultCodeSuccess success.
ReturnCodeFail fail.
ReturnCodeSuccess success.