[ {
  Total => 0.07,
  Set => [ { a=> 0.02, b => 0.07}]
  },
  { 
  Total => 0.27,
  Set => [ { c => 0.20}]
  },
  { 
  Total => 0.27,  #repeat since it span's two "subsets"
  Set => [ { c=> 0.20 }]
  }, 
  { 
  Total => 0.38,
  Set => [ { d => 0.11 } ] 
  },
  #etc
]