Constructor
new AAIGridMetadata()
    Constructs a new container for AAIGrid metadata.
    
    Members
cellsize :Number
    The length of one side of a square cell (resolution of the grid).
    Type:
- Number
 
ncols :Number
    Number of columns in the grid.
    Type:
- Number
 
NODATA_value :Number|undefined
    The value that is regarded as "missing" or "not applicable".
This value is optional. If not present, its value is 
    undefined.
Type:
- Number | undefined
 
nrows :Number
    Number of rows in the grid.
    Type:
- Number
 
xllcorner :Number
    The western edge (left), x-coordinate
    Type:
- Number
 
yllcorner :Number
    The southern edge (bottom), y-coordinate
    Type:
- Number