func (p *Importer) Import(path string) (*types.Package, error) {
	return p.ImportFrom(path, ".", 0)  
}
Import(path) is a shortcut for ImportFrom(path, ".", 0).
package srcimporter
import (
	"fmt"
	"go/ast"
	"go/build"
	"go/importer"
	"go/parser"
	"go/token"
	"go/types"
	"io"
	"os"
	"path/filepath"
	"sync"
)
type Importer struct {
	ctxt     *build.Context
	fset     *token.FileSet
	sizes    types.Sizes
	packages map[string]*types.Package
}
func New(ctxt *build.Context, fset *token.FileSet, packages map[string]*types.Package) *Importer {
	return &Importer{
		ctxt:     ctxt,
		fset:     fset,
		sizes:    types.SizesFor(ctxt.Compiler, ctxt.GOARCH),  
		packages: packages,
	}
}
var importing types.Package