[3] pry(main)> def test( data = nil, content_type: 'application/json', charset: 'UTF-8' )
[3] pry(main)*   puts data
[3] pry(main)*   puts content_type
[3] pry(main)*   puts charset
[3] pry(main)* end  
=> :test
[4] pry(main)> test( { token: "blabla" } )
ArgumentError: unknown keyword: token
from (pry):5:in `test'

 ha = { token: "123123" }
test( ha )

def test( data, content_type: 'application/json', charset: 'UTF-8' )
...