Returns whether content marked with ocgOrOcmd is visible under state.
public bool IsVisible(CosObject? ocgOrOcmd, PdfOptionalContentState state)
The value of an OC entry (XObject, annotation) or the property list of an /OC marked-content section: a group,
a membership dictionary, or a reference to one. null and anything else is not optional content: visible.
States from this properties view.
false only when the content is optional and hidden.ISO 32000-2 §8.11.2, §8.11.3.2 and §8.11.3.3. A group listed in OCGs gives its state, or has no effect when its intent
does not count (§8.11.2.3). A membership dictionary evaluates its visibility expression, else its policy over its groups; a
malformed expression falls back to the policy (VisibilityExpressionInvalid). A group dictionary not listed in
OCGs is not optional content (OptionalContentGroupNotListed). Allocation-free once the membership is compiled.