def load config_file
      config_file ||= @config_file
      newsets = YAML::load_file(config_file)
      raise 'Config file was not valid YAML' if newsets == false
      newsets.deep_symbolize.each_pair do |key, value|
        varname = "@#{key.to_s}".to_sym
        unless self.instance_variables.include? varname
          raise SettingsError.new "Key #{key.to_s} in settings file is not valid"
        end
        self.instance_variable_set(varname, value)
      end
    end
def load config_file
      config_file ||= @config_file
      newsets = YAML::load_file(config_file)
      raise 'Config file was not valid YAML' if newsets == false
      newsets.deep_symbolize.each_pair do |key, value|
        varname = "@#{key.to_s}".to_sym
        unless self.instance_variables.include? varname
          raise SettingsError.new "Key #{key.to_s} in settings file is not valid"
        end
        self.instance_variable_set(varname, value)
      end
    end
Loads settings from a YAML config file. If no file is
 specified, the default location ('~/.biopsyrc') is used.
 Settings loaded from the file are merged into any
 previously loaded settings.