mxConstraint reports '=' (instead of '==') as "unused parameter"

hi,
If the user makes the mistake of using = instead of == in a constraint, they get the error
unused argument(s) (con_a = con_b)

It would be nicer (if possible) to report

Error: A constraint must be of the form: 'exp1 [<, ==, >] exp2'

Example code to generate possible buglet
mxModel("fun",
mxMatrix("Full", 1,1, free=F, values = 0, label="a", name="con_a"),
mxMatrix("Full", 1,1, free=T, values = 1, label="b", name="con_b"),
mxAlgebra(expression= 2*con_b, name="con"),
mxConstraint(con_a = con_b, name="a_eq_b"),
mxFIMLObjective(covariance="expectedCov", means="expectedMeans", dimnames = NA, thresholds = NA)
)