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: command.rb
    path of file: ./repos/gel/lib/gel
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require_relative "compatibility"
require_relative "error"

class Gel::Command
  def self.run(command_line)
    command_line = command_line.dup
    if command_name = extract_word(command_line)
      const =
    
  def self.run(command_line)
    command_line = command_line.dup
    if command_name = extract_word(command_line)
      const = command_name.downcase.sub(/^./, &:upcase).gsub(/[-_]./) { |s| s[1].upcase }
      if const =~ /\A[a-z]+\z/i
        if Gel::Command.const_defined?(const, false)
          command = Gel::Command.const_get(const, false).new
          command.run(command_line)
        elsif Gel::Environment.activate_for_executable(["gel-#{command_name}", command_name])
          command_name = "gel-#{command_name}" if Gel::Environment.find_executable("gel-#{command_name}")
          command = Gel::Command::Exec.new
          command.run([command_name, *command_line])
        else
          raise Gel::Error::UnknownCommandError.new(command_name: command_name)
        end