Example of how to use Ruby's RestClient with POST parameters, basic authorization, HTTP headers, and JSON:
```ruby
response = RestClient::Request.new({
method: :post,
url: 'https://xyz,
user: 'someone',
password: 'mybirthday',
payload: { post_this: 'some value', post_that: 'other value' },
headers: { :accept => :json, content_type: :json }
}).execute do |response, request, result|
case response.code
when 400
[ :error, parse_json(response.to_str) ]
when 200
[ :success, parse_json(response.to_str) ]
else
fail "Invalid response #{response.to_str} received."
end
end
```