Multi-Support Excitation Pattern
<uml> abstract class ElementLoad abstract class TimeSeries LoadPattern <|-- MultipleSupportExcitation LoadPattern <|-- UniformExcitation MultipleSupportExcitation o- GroundMotion MultipleSupportExcitation o- ImposedMotionSP SP_Constraint <|-- ImposedMotionSP LoadPattern o- "one" TimeSeries LoadPattern o- ElementLoad LoadPattern o- NodalLoad LoadPattern o- SP_Constraint </uml>