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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def emit_code_from_ir(sql_query_tree, compiler_metadata):
 """Return a SQLAlchemy Query from a passed SqlQueryTree. Args: sql_query_tree: SqlQueryTree, tree representation of the query to emit. compiler_metadata: SqlMetadata, SQLAlchemy specific metadata. Returns: SQLAlchemy Query """

    context = CompilationContext(
        query_path_to_selectable=dict(),
        query_path_to_location_info=sql_query_tree.query_path_to_location_info,
        query_path_to_output_fields=sql_query_tree.query_path_to_output_fields,
        query_path_to_filters=sql_query_tree.query_path_to_filters,
        query_path_to_node=sql_query_tree.query_path_to_node,
        compiler_metadata=compiler_metadata,
    )

    return _query_tree_to_query(sql_query_tree.root, context)