docs: def xml(self, indent = ""):
          """Produce XML output for the profile"""
          xml = "\n" + indent + "<profile>\n"
          xml += indent + " <input>\n"
          for inputtemplate in self.input:
              xml += inputtemplate.xml(indent +"    ") + "\n"
          xml += indent + " </input>\n"
          xml += indent + " <output>\n"
          for outputtemplate in self.output:
              xml += outputtemplate.xml(indent +"    ") + "\n" #works for ParameterCondition as well!
          xml += indent + " </output>\n"
          xml += indent + "</profile>\n"
          return xml