{
  "title": "GD M:N project testing",
  "datasets": [
    {
      "type": "dataset",
      "id": "dataset.visibility",
      "columns": [
        {
          "type": "anchor",
          "id": "attr.visibility.id"
        },
        {
          "type": "label",
          "name": "visibility_id",
          "id": "label.visibility.id",
          "reference": "attr.visibility.id"
        },
        {
          "type": "reference",
          "name": "perm_user_id",
          "dataset": "dataset.permission_users"
        },
        {
          "type": "reference",
          "name": "commit_id",
          "dataset": "dataset.commits"
        }
      ]
    },
    {
      "type": "dataset",
      "id": "dataset.users",
      "columns": [
        {
          "type": "anchor",
          "id": "attr.users.id"
        },
        {
          "type": "label",
          "name": "user_id",
          "id": "label.users.id",
          "reference": "attr.users.id"
        },
        {
          "type": "label",
          "id": "label.users.id.email",
          "name": "email",
          "reference": "attr.users.id",
          "default_label" : true
        }
      ]
    },
    {
      "type": "dataset",
      "id": "dataset.permission_users",
      "columns": [
        {
          "type": "anchor",
          "id": "attr.permission.id"
        },
        {
          "type": "label",
          "name": "perm_user_id",
          "id": "label.permission.id",
          "reference": "attr.permission.id"
        },
        {
          "type": "label",
          "id": "label.permission.id.email",
          "name": "email",
          "reference": "attr.permission.id",
          "default_label" : true
        }
      ]
    },
    {
      "type": "dataset",
      "id": "dataset.commits",
      "columns": [
        {
          "type": "anchor",
          "id": "attr.commits.id"
        },
        {
          "type": "label",
          "id": "label.commits.id",
          "name": "commit_id",
          "reference": "attr.commits.id",
          "default_label" : true
        },
        {
          "type": "fact",
          "id": "fact.commits.lines_changed",
          "name": "lines_changed"
        },
        {
          "type": "reference",
          "name": "user_id",
          "dataset": "dataset.users"
        }
      ]
    }
  ]
}