code: def arch_prefixes(self):
          
  
          archs = self.archs(as_list=True)
          prefixes = []
  
          for i in range(1, len(archs)+1):
              prefixes.append(archs[:i])
  
          return prefixes
docs: Return the initial 1, 2, ..., N architectures as a prefix list
  
          For arch1/arch2/arch3, this returns
          [arch1],[arch1/arch2],[arch1/arch2/arch3]