Remove unused code to increase coverage percentage

apps/explorer/lib/explorer/chain/credit.ex

@@ -22,6 +22,4 @@ defmodule Explorer.Chain.Credit do
   def refresh do
     SQL.query!(Repo, "REFRESH MATERIALIZED VIEW CONCURRENTLY credits;", [], timeout: 120_000)
   end
-
-  def null, do: %__MODULE__{value: Decimal.new(0), count: 0}
 end

apps/explorer/lib/explorer/chain/debit.ex

@@ -22,6 +22,4 @@ defmodule Explorer.Chain.Debit do
   def refresh do
     SQL.query!(Repo, "REFRESH MATERIALIZED VIEW CONCURRENTLY debits;", [], timeout: 120_000)
   end
-
-  def null, do: %__MODULE__{value: Decimal.new(0), count: 0}
 end

apps/explorer/lib/explorer/chain/internal_transaction.ex

@@ -35,6 +35,4 @@ defmodule Explorer.Chain.InternalTransaction do
     |> foreign_key_constraint(:from_address_id)
     |> unique_constraint(:transaction_id, name: :internal_transactions_transaction_id_index_index)
   end
-
-  def null, do: %__MODULE__{}
 end

coveralls.json

@@ -1,7 +1,7 @@
 {
   "coverage_options": {
     "treat_no_relevant_lines_as_covered": true,
-    "minimum_coverage": 77.8
+    "minimum_coverage": 83.2
   },
   "terminal_options": {
     "file_column_width": 120