Failed when use casting in a equal expression to constraint a random variable

[LeeKaiXuan]

Description

When use casting in a equal expression to constraint a random variable, PSSGen reports a method is not implemented.

Scenario Code

action wrapper {
    rand bit msb;
    activity {
        do example with { val == ((bit [4])msb << 3); };
    }
}
action example {
    rand bit [4] val;
    exec body ASM =
"""
val = {{val}}
""";
}

Expected Output or Behaviour

val = 8

Error Message from PSSGen or JAVA (Optional)

PSSExpression.isRandomable(), Ln15: PSSCastExpression.isRandomable() is not implemented

[LeeKaiXuan]

Workaround

Use in expression instead of equal expression to bypass the checker.
Original:

do example with { val == ((bit [4])msb << 3); };

Becomes:

do example with { val in [(bit [4])msb << 3]; };