code: def get_modelinsertion(cls, model, indent) -> str:
          
          texts = []
          for name in ('inputs', 'fluxes', 'states'):
              subsequences = getattr(model.sequences, name, None)
              if subsequences:
                  texts.append(
                      cls.get_subsequencesinsertion(subsequences, indent))
          return '\n'.join(texts)
docs: Return the insertion string required for the given application model.
  
          >>> from hydpy.auxs.xmltools import XSDWriter
          >>> from hydpy import prepare_model
          >>> model = prepare_model('hland_v1')
          >>> print(XSDWriter.get_modelinsertion(model, 1))   # doctest: +ELLIPSIS
              <element name="inputs"
                       minOccurs="0">
                  <complexType>
                      <sequence>
                          <element
                              name="p"
                              minOccurs="0"/>
          ...
              </element>
              <element name="fluxes"
                       minOccurs="0">
          ...
              </element>
              <element name="states"
                       minOccurs="0">
          ...
              </element>