Mock a CICS file read and provide fake results

MOCK CICS READ 
    DATASET('FILENAME') 
    RIDFLD(WS-KEY) 
    INTO(WS-RECORD) 
    LENGTH(256)
    MOVE 'AAAAABBBBBCCCCCDDDDDEEEEE' TO WS-RECORD
END-MOCK
. . .
EXPECT WS-FIELD-3 TO BE 'CCCCC'
VERIFY CICS READ 
    DATASET('FILENAME')
    RIDFLD(WS-KEY) 
    INTO(WS-RECORD) 
    LENGTH(256)
HAPPENED ONCE