Renamed "verify" functions to "validate".

Another idea for defining the fields in records
would be to create a class method that would instantiate
the individual fields at instance creation rather than
during class definition. This would use less memory when
there are no Record objects being used.

Storing each Field after it's instantiated into a List, as
well as a Dict would remove the necessity for counting the
Field instantiation order, since the List would hold them in
their proper order.

pyaccuwage/model.py

@@ -1,4 +1,4 @@
-from fields import Field
+from fields import Field, ValidationError
 import copy
 import pdb
 
@@ -51,8 +51,11 @@ class Model(object):
                  custom_validator(f)
 
     def output(self):
-        return ''.join([self.record_identifier] + [field.get_data() for field in self.get_sorted_fields()])
-    
+        result = ''.join([self.record_identifier] + [field.get_data() for field in self.get_sorted_fields()])
+        if len(result) != 512:
+            raise ValidationError("Record result length not equal to 512 bytes")
+        return result
+
     def read(self, fp):
         for field in self.get_sorted_fields():
             field.read(fp)