FIX code review

app/imports/admins/import_course_member_excel.rb

@@ -1,20 +0,0 @@
-class Admins::ImportCourseMemberExcel < BaseImportXlsx
-  Data = Struct.new(:student_id, :name, :course_id, :role, :course_group_name, :school_id)
-
-  def read_each(&block)
-    sheet.each_row_streaming(pad_cells: true, offset: 1) do |row|
-      data = row.map(&method(:cell_value))[0..5]
-      block.call Data.new(*data)
-    end
-  end
-
-  private
-
-  def check_sheet_valid!
-    raise_import_error('请按照模板格式导入') if sheet.row(1).size != 6
-  end
-
-  def cell_value(obj)
-    obj&.cell_value&.to_s&.strip
-  end
-end