@Override
  public void visitMapEntryExpression(MapEntryExpression expr) {
    MapEntryExpression conversion =
        new MapEntryExpression(
            convert(expr.getKeyExpression()),
            convert(expr.getValueExpression()));

    conversion.setSourcePosition(expr);
    result = recordNa(conversion);
  }
Rewrites explicit ("assert x > 3") and implicit ("x > 3") condition
statements. Replacing the original statement with the rewritten one is up
to clients.

@author Peter Niederwieser
spock-core/src/main/java/org/spockframework/compiler/ConditionRewriter.java