How to close an open workbook using rubyXL gem

Question

I have used below code to read and write from worksheet.But when the worksheet is already in open and if I try to run the code its failing because of permission error.I want to make sure when I hit the run the opened excel file should close.

require 'rubyXL'

# reading from excel


workbook=RubyXL::Parser.parse("#{Dir.pwd}/test.xlsx")

# here I want to make sure the excel get closed 

#workbook.close -> this code not working

worksheet= workbook['Sheet1']

header_row=worksheet.sheet_data[1]

header_data=Array.new

header_row.size.times do |i|

  header_data<<header_row[i].value
end

#writing to excel

worksheet.add_cell(0,2,'Pass')
worksheet.add_cell(0,3,'Fail')
workbook.write("#{Dir.pwd}/test.xlsx")