lib/fit4ruby/GlobalFitMessage.rb
def field(number, type, name, opts = {})
      field = Field.new(type, name, opts)
      register_field_by_name(field, name)
      register_field_by_number(field, number)
    end
def field(number, type, name, opts = {})
      field = Field.new(type, name, opts)
      register_field_by_name(field, name)
      register_field_by_number(field, number)
    end
Create a new GlobalFitMessage definition.
 @param name [String] name of the FIT message
 @param number [Fixnum] global message number
 Two GlobalFitMessage objects are considered equal if they have the same
 number, name and list of named fields.
 Define a new Field for this message definition.