It returns the substring (String formatting functions). 
 
void setLength(ParameterValue *v)
 
void setPosition(ParameterValue *v)
 
Substring()
It initializes a new Substring. 
 
The ParameterValueType uses WFS-Filter expressions to give values for SE graphic parameters. 
 
void setStringValue(ParameterValue *v)
 
The "ParameterValueType" uses WFS-Filter expressions to give values for SE graphic parameters...