diff --git a/masque/builder/device_library.py b/masque/builder/device_library.py
index 0afed5a..d86a6cc 100644
--- a/masque/builder/device_library.py
+++ b/masque/builder/device_library.py
@@ -3,13 +3,13 @@ DeviceLibrary class for managing unique name->device mappings and
  deferred loading or creation.
 """
 from typing import Dict, Callable, TypeVar, TYPE_CHECKING
-from typing import Any, Tuple, Union, Iterator
+from typing import Any, Tuple, Union, Iterator, Mapping
 import logging
 from pprint import pformat
 from abc import ABCMeta, abstractmethod
 
 from ..error import DeviceLibraryError
-from ..library import Library
+from ..library import Library, LazyLibrary
 from ..builder import Device, DeviceRef
 from .. import Pattern
 
@@ -18,6 +18,7 @@ logger = logging.getLogger(__name__)
 
 
 DL = TypeVar('DL', bound='LazyDeviceLibrary')
+DL2 = TypeVar('DL2', bound='LazyDeviceLibrary')
 LDL = TypeVar('LDL', bound='LibDeviceLibrary')
 
 
diff --git a/masque/file/gdsii.py b/masque/file/gdsii.py
index e96a082..416cb18 100644
--- a/masque/file/gdsii.py
+++ b/masque/file/gdsii.py
@@ -457,7 +457,7 @@ def _shapes_to_elements(
                 layer=(layer, data_type),
                 xy=xy,
                 path_type=path_type,
-                width=width,
+                width=int(width),
                 extension=extension,
                 properties=properties,
                 )
diff --git a/masque/file/utils.py b/masque/file/utils.py
index 8d866a9..b475b47 100644
--- a/masque/file/utils.py
+++ b/masque/file/utils.py
@@ -138,7 +138,7 @@ def dose2dtype(
         library = WrapROLibrary(library)
 
     # Get a table of (id(pat), written_dose) for each pattern and subpattern
-    sd_table = make_dose_table(library.find_topcells(), library)
+    sd_table = make_dose_table(library.find_toplevel(), library)
 
     # Figure out all the unique doses necessary to write this pattern
     #  This means going through each row in sd_table and adding the dose values needed to write
diff --git a/masque/library.py b/masque/library.py
index f4a381b..08a982f 100644
--- a/masque/library.py
+++ b/masque/library.py
@@ -684,7 +684,7 @@ class LazyLibrary(MutableLibrary):
     def __repr__(self) -> str:
         return '<LazyLibrary with keys ' + repr(list(self.dict.keys())) + '>'
 
-    def precache(self: L) -> L:
+    def precache(self: LL) -> LL:
         """
         Force all patterns into the cache
 
@@ -695,7 +695,7 @@ class LazyLibrary(MutableLibrary):
             _ = self.dict.__getitem__(key)
         return self
 
-    def clear_cache(self: L) -> L:
+    def clear_cache(self: LL) -> LL:
         """
         Clear the cache of this library.
         This is usually used before modifying or deleting cells, e.g. when merging