class Spoom::LSP::Client

def signatures(uri, line, column)
  json = send(Request.new(
    next_id,
    'textDocument/signatureHelp',
    {
      'textDocument' => {
        'uri' => uri,
      },
      'position' => {
        'line' => line,
        'character' => column,
      },
    }
  ))
  json['result']['signatures'].map { |loc| SignatureHelp.from_json(loc) }
end