[
  {
    "x_series": "x",
    "y_series": "y",
    "histfunc": "count",
    "type": "histogram",
    "name": "count"
  },
  {
    "x_series": "x",
    "y_series": "y",
    "histfunc": "sum",
    "type": "histogram",
    "name": "sum"
  }
]
