You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: span.rb
    path of file: ./repos/dd-trace-rb/lib/datadog/opentracer
    
    the code of the file until where you have to start completion: require 'time'

require_relati
    
      def set_tag(key, value)
        # Special cases to convert opentracing tags to datadog tags
        case key
        when 'error'
          # Opentracing supports and `error: <bool>` tag, we need to convert to span status
          # DEV: Do not return, we want to still set the `error` tag as they requested
          datadog_span.status = value ? Datadog::Tracing::Metadata::Ext::Errors::STATUS : 0
        end