Fix imports

tests/unittests/expressions/test_linearization.py

@@ -1,14 +1,11 @@
 from unittest.mock import Mock
 
 import pytest
-from pydantic._internal._validators import pattern_bytes_validator
-from unittests.expressions.test_expressions import StructureProvider
 
 from andromede.expression import ExpressionNode, LiteralNode, literal, var
 from andromede.expression.expression import (
     ComponentVariableNode,
     NoScenarioIndex,
-    ProblemVariableNode,
     TimeShift,
     comp_param,
     comp_var,
@@ -22,6 +19,8 @@
 from andromede.simulation.linear_expression import LinearExpression, Term
 from andromede.simulation.linearize import ParameterGetter, linearize_expression
 
+from .test_expressions import StructureProvider
+
 P = comp_param("c", "p")
 X = comp_var("c", "x")
 Y = comp_var("c", "y")