code: def get_subsequencesinsertion(cls, subsequences, indent) -> str:
          
          blanks = ' ' * (indent*4)
          lines = [f'{blanks}<element name="{subsequences.name}"',
                   f'{blanks}         minOccurs="0">',
                   f'{blanks}    <complexType>',
                   f'{blanks}        <sequence>']
          for sequence in subsequences:
              lines.append(cls.get_sequenceinsertion(sequence, indent + 3))
          lines.extend([f'{blanks}        </sequence>',
                        f'{blanks}    </complexType>',
                        f'{blanks}</element>'])
          return '\n'.join(lines)
docs: Return the insertion string required for the given group of
          sequences.
  
          >>> from hydpy.auxs.xmltools import XSDWriter
          >>> from hydpy import prepare_model
          >>> model = prepare_model('hland_v1')
          >>> print(XSDWriter.get_subsequencesinsertion(
          ...     model.sequences.fluxes, 1))    # doctest: +ELLIPSIS
              <element name="fluxes"
                       minOccurs="0">
                  <complexType>
                      <sequence>
                          <element
                              name="tmean"
                              minOccurs="0"/>
                          <element
                              name="tc"
                              minOccurs="0"/>
          ...
                          <element
                              name="qt"
                              minOccurs="0"/>
                      </sequence>
                  </complexType>
              </element>