class Console::Resolver

def self.default_resolver(logger, env = ENV)

@returns [Resolver] If there were custom logging levels, then the created resolver is returned.
@returns [Nil] If there were no custom logging levels specified in the environment.

@parameter env [Hash] The environment to read levels from.
@parameter logger [Logger] A logger instance to set the logging levels on.

You can enable all log levels for a given class by using `CONSOLE_ON=MyClass`. Similarly you can disable all logging using `CONSOLE_OFF=MyClass`.

e.g. `CONSOLE_WARN=Acorn,Banana CONSOLE_DEBUG=Cat` will set the log level for the classes Acorn and Banana to `warn` and Cat to `debug`. This overrides the default log level.

You can change the log level for different classes using CONSOLE_$LEVEL env vars. 
def self.default_resolver(logger, env = ENV)
	# Find all CONSOLE_$LEVEL variables from environment:
	levels = logger.class::LEVELS
		.map{|label, level| [level, env["CONSOLE_#{label.upcase}"]&.split(",")]}
		.to_h
		.compact
	
	off_klasses = env["CONSOLE_OFF"]&.split(",")
	on_klasses = env["CONSOLE_ON"]&.split(",")
	
	resolver = nil
	
	# If we have any levels, then create a class resolver, and each time a class is resolved, set the log level for that class to the specified level:
	if on_klasses&.any?
		resolver ||= Resolver.new
		
		resolver.bind(on_klasses) do |klass|
			logger.enable(klass, logger.class::MINIMUM_LEVEL - 1)
		end
	end
	
	if off_klasses&.any?
		resolver ||= Resolver.new
		
		resolver.bind(off_klasses) do |klass|
			logger.disable(klass)
		end
	end
	
	levels.each do |level, names|
		resolver ||= Resolver.new
		
		resolver.bind(names) do |klass|
			logger.enable(klass, level)
		end
	end
	
	return resolver
end