Returns an {@code Nullable} describing the given non-{@code null}
value.
@param value the value to describe, which must be non-{@code null}
@param U the type of the value
@return an {@code Nullable} with the value present
@throws NullPointerException if value is {@code null}
Returns an {@code Nullable} describing the given non-{@code null} value.
@param value the value to describe, which must be non-{@code null} @param U the type of the value @return an {@code Nullable} with the value present @throws NullPointerException if value is {@code null}