RF: Make AssertEqual a LibraryBaseInterface

Author: effigies

nipype/interfaces/utility/base.py

@@ -16,11 +16,10 @@
 import os
 import re
 import numpy as np
-import nibabel as nb
 
 from ..base import (traits, TraitedSpec, DynamicTraitedSpec, File, Undefined,
                     isdefined, OutputMultiPath, InputMultiPath, BaseInterface,
-                    BaseInterfaceInputSpec, Str, SimpleInterface)
+                    BaseInterfaceInputSpec, Str, SimpleInterface, LibraryBaseInterface)
 from ..io import IOBase, add_traits
 from ...utils.filemanip import ensure_list, copyfile, split_filename
 
@@ -412,11 +411,12 @@ class AssertEqualInputSpec(BaseInterfaceInputSpec):
     volume2 = File(exists=True, mandatory=True)
 
 
-class AssertEqual(BaseInterface):
+class AssertEqual(LibraryBaseInterface):
     input_spec = AssertEqualInputSpec
+    _pkg = 'nibabel'
 
     def _run_interface(self, runtime):
-
+        import nibabel as nb
         data1 = nb.load(self.inputs.volume1).get_data()
         data2 = nb.load(self.inputs.volume2).get_data()