nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/autodiff/samediff/SameDiff.java
public void addAsPlaceHolder(String varName) {
        placeHolderVarNames.add(varName);
        if (getVariable(varName) != null && getVariable(varName).getShape() != null) {
            placeHolderOriginalShapes.put(varName, getVariable(varName).getShape());
        }
    }
public void addAsPlaceHolder(String varName) {
        placeHolderVarNames.add(varName);
        if (getVariable(varName) != null && getVariable(varName).getShape() != null) {
            placeHolderOriginalShapes.put(varName, getVariable(varName).getShape());
        }
    }
Add  this vertex id as a place holder

@param varName the vertex id to add