code: def _query_builder(self,
                         start_date=None,
                         end_date=None,
                         clipper=None
                          ):
          
          search_string='format=json&lang=fr&q='
          if (start_date is not None):
              if(end_date is not None):
                  search_string+='entre+'+start_date+'+et+'+end_date
              else:
                  search_string+=start_date
          elif(end_date is not None): 
              search_string+=end_date
          
          if(clipper.query is not None):
              query=clipper.query.replace(' ','+')
              search_string+='+'+query
          if(clipper.bbox is not None):
              search_string+='&box='+clipper.bbox
  
          return search_string
docs: Builds the proper search syntax (query) for Landsat theia API