# File lib/simplecov/configuration.rb, line 189
  def parse_filter(filter_argument=nil, &filter_proc)
    if filter_argument.kind_of?(SimpleCov::Filter)
      filter_argument
    elsif filter_argument.kind_of?(String)
      SimpleCov::StringFilter.new(filter_argument)
    elsif filter_proc
      SimpleCov::BlockFilter.new(filter_proc)
    else
      raise ArgumentError, "Please specify either a string or a block to filter with"
    end      
  end