def get_context(self, arr, expr, context):
expression_names = [x for x in self.get_expression_names(expr) if x not in set(context.keys()).union(['<STR_LIT:i>'])]<EOL>if len(expression_names) != <NUM_LIT:1>:<EOL><INDENT>raise ValueError('<STR_LIT>')<EOL><DEDENT>return {expression_names[<NUM_LIT:0>]: arr}<EOL>
Returns a context dictionary for use in evaluating the expression.

:param arr: The input array.
:param expr: The input expression.
:param context: Evaluation context.