dirty commit: can't get references to work correctly between any tables

app/presenters/dashboard/analyze/graph/students_by_income.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+module Analyze
+  module Graph
+    class StudentsByIncome
+      attr_reader :incomes
+
+      def initialize(incomes:)
+        @incomes = incomes
+      end
+
+      def to_s
+        "Students by income"
+      end
+
+      def slug
+        "students-by-income"
+      end
+
+      def columns
+        [].tap do |array|
+          incomes.each do |income|
+            array << column_for_income_code(code: income.slug)
+          end
+          array << Analyze::Graph::Column::AllStudent
+        end
+      end
+
+      private
+
+      def column_for_income_code(code:)
+        CFR[code.to_s]
+      end
+
+      CFR = {
+        "economically-disadvantaged-y" => Analyze::Graph::Column::IncomeColumn::Disadvantaged,
+        "economically-disadvantaged-n" => Analyze::Graph::Column::IncomeColumn::NotDisadvantaged,
+        "unknown" => Analyze::Graph::Column::IncomeColumn::Unknown
+      }.freeze
+    end
+  end
+end