Add COPY statement inside sql function AND/OR call function within function

DUMMY DATA

tblA (filled)

create table tblA (id varchar(5) PRIMARY KEY, method text, species varchar(10), location    
text);
insert into tblA values ('1a', 'mtd1', 'sp1', 'locA'),('1b', 'mtd1', 'sp2', 'locC'),('1c',  
'mtd2', 'sp3', 'locB'),('1d', 'mtd1', 'sp1', 'locB'),('1e', 'mtd2', 'sp5', 'locA');

retrieve_info_tbl (empty)

create table retrieve_info_tbl (id varchar(5) PRIMARY KEY, method text, ind varchar(10),  
location text);

SELECT * FROM retrieve_info('mtd1','sp1');

OUTPUT

retrieve_info(mtd1, sp3)

id | method | ind | location
----------------------------
1a | mtd1   | sp3 | locA
1d | mtd1   | sp3 | locB

CREATE FUNCTION print_out(x TEXT, y TEXT) RETURNS void AS $$COPY (SELECT * FROM retrieve_info(x,y)) TO 'myfilepath/test.csv'    WITH CSV HEADER;
$$ LANGUAGE 'sql';

SELECT * FROM print_out('mtd1','sp1');

Johannes