ERROR when using E'xxxx'

[BaiShaoqi]

Expected behavior

CREATE FUNCTION

Actual behavior

ERROR:  syntax error at or near "#"
LINE 2: # container: plc_python_shared
        ^

Step to reproduce the behavior

CREATE OR REPLACE FUNCTION newline_lf() RETURNS integer AS
# container: plc_python_shared
E'x = 100\ny = 23\nreturn x + y\n'
LANGUAGE plcontainer;