public boolean tryCreate() {
    return tryReserve(maximum);
  }
Should be called when a new connection would be nice to have when count is under maximum.
Caller should only create a connection if this method returns {@code true}. If connection
creation fails then {@link #cancelTryCreate} must be called to revert the count increase.

@return {@code true} if count was under maximum and we increased it, otherwise {@code false}.
geode-core/src/main/java/org/apache/geode/cache/client/internal/pooling/ConnectionAccounting.java