def fix(problem)
prev_token = problem[:start_token].prev_token
prev_code_token = problem[:start_token].prev_code_token
next_token = problem[:end_token].next_token
next_code_token = problem[:end_token].next_code_token
var_token = problem[:var_token]
tokens.delete(problem[:start_token])
tokens.delete(problem[:end_token])
prev_token.next_token = var_token unless prev_token.nil?
prev_code_token.next_code_token = var_token unless prev_code_token.nil?
next_code_token.prev_code_token = var_token unless next_code_token.nil?
next_token.prev_token = var_token unless next_token.nil?
var_token.type = :VARIABLE
var_token.next_token = next_token
var_token.next_code_token = next_code_token
var_token.prev_code_token = prev_code_token
var_token.prev_token = prev_token
end