docs: def build(self, builder):
          """Build XML by appending to builder"""
          params = dict(MetaDataVersionOID=str(self.metadata_version_oid),
                        StudyOID="%s (%s)" % (self.projectname, self.environment,),
                        )
  
          # mixins
          self.mixin_params(params)
  
          builder.start("ClinicalData", params)
          # Ask children
          if self.subject_data:
              for subject in self.subject_data:
                  subject.build(builder)
          # Add the Annotations
          if self.annotations is not None:
              self.annotations.build(builder)
          builder.end("ClinicalData")