public SpatialStrategy(SpatialContext ctx,String fieldName){
  if (ctx == null)   throw new IllegalArgumentException("ctx is required");
  this.ctx=ctx;
  if (fieldName == null || fieldName.length() == 0)   throw new IllegalArgumentException("fieldName is required");
  this.fieldName=fieldName;
}

public SpatialStrategy ( SpatialContext ctx , String fieldName ) { if ( ctx == null ) throw new IllegalArgumentException ( "ctx is required" ) ; this . ctx = ctx ; if ( fieldName == null || fieldName . length ( ) == 0 ) throw new IllegalArgumentException ( "fieldName is required" ) ; this . fieldName = fieldName ; }
constructs the spatial strategy with its mandatory arguments .
